Correction: Differences and commonalities in plasma membrane recruitment of the two morphogenetically distinct retroviruses HIV-1 and MMTV [Additions and Corrections]
Discussion,” “with the PS 2?-acyl chain” should read as “with the 2'-acyl chain.” In the last paragraph under “Discussion,” “PI4,5P2” should be corrected to “PI4,5P2.” (Source: Journal of Biological Chemistry)
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Petra Junkova, Roman Pleskot, Jan Prchal, Jakub Sys, Tomaš Ruml Tags: Additions and Corrections Source Type: research

Correction: Betaine is accumulated via transient choline dehydrogenase activation during mouse oocyte meiotic maturation. [Additions and Corrections]
VOLUME 292 (2017) PAGES 13784–13794The authors recently became aware that the measurements reported in Fig. 7 had been provided to the authors with the incorrect units stated. The units stated by the laboratory that had been contracted to do the measurements were ng/ml (in 200 µl of sample), whereas the actual units for the values that were provided were total pmoles in each sample. This resulted in the calculated amounts of betaine per oocyte that were reported (in pmoles/oocyte) in Fig. 7 being approximately 48% higher than the amounts calculated using the correct units. This error did not affect the betaine ...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Taylor McClatchie, Megan Meredith, Mariame O. Ouedraogo, Sandy Slow, Michael Lever, Mellissa R. W. Mann, Steven H. Zeisel, Jacquetta M. Trasler, Jay M. Baltz Tags: Additions and Corrections Source Type: research

The Parkinson's disease-associated kinase LRRK2 regulates genes required for cell adhesion, polarization, and chemotaxis in activated murine macrophages [Immunology]
Leucine-rich repeat kinase 2 (LRRK2) encodes a complex protein that includes kinase and GTPase domains. Genome-wide association studies have identified dominant LRRK2 alleles that predispose their carriers to late-onset idiotypic Parkinson's disease (PD) and also to autoimmune disorders such as Crohn's disease. Considerable evidence indicates that PD initiation and progression involve activation of innate immune functions in microglia, which are brain-resident macrophages. Here we asked whether LRRK2 modifies inflammatory signaling and how this modification might contribute to PD and Crohn's disease. We used RNA-Seq–...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Daniel R. Levy, Atul Udgata, Panagiotis Tourlomousis, Martyn F. Symmons, Lee J. Hopkins, Clare E. Bryant, Nicholas J. Gay Tags: Gene Regulation Source Type: research

Disrupting phosphatase SHP2 in macrophages protects mice from high-fat diet-induced hepatic steatosis and insulin resistance by elevating IL-18 levels [Cell Biology]
Chronic low-grade inflammation plays an important role in the pathogenesis of type 2 diabetes. Src homology 2 domain-containing tyrosine phosphatase-2 (SHP2) has been reported to play diverse roles in different tissues during the development of metabolic disorders. We previously reported that SHP2 inhibition in macrophages results in increased cytokine production. Here, we investigated the association between SHP2 inhibition in macrophages and the development of metabolic diseases. Unexpectedly, we found that mice with a conditional SHP2 knockout in macrophages (cSHP2-KO) have ameliorated metabolic disorders. cSHP2-KO mice...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Wen Liu, Ye Yin, Meijing Wang, Ting Fan, Yuyu Zhu, Lihong Shen, Shuang Peng, Jian Gao, Guoliang Deng, Xiangbao Meng, Lingdong Kong, Gen-Sheng Feng, Wenjie Guo, Qiang Xu, Yang Sun Tags: Molecular Bases of Disease Source Type: research

Diabetes enhances translation of Cd40 mRNA in murine retinal Muller glia via a 4E-BP1/2-dependent mechanism [Protein Synthesis and Degradation]
Activation of the immune costimulatory molecule cluster of differentiation 40 (CD40) in Müller glia has been implicated in the initiation of diabetes-induced retinal inflammation. Results from previous studies support that CD40 protein expression is elevated in Müller glia of diabetic mice; however, the mechanisms responsible for this increase have not been explored. Here, we evaluated the hypothesis that diabetes augments translation of the Cd40 mRNA. Mice receiving thiamet G (TMG), an inhibitor of the O-GlcNAc hydrolase O-GlcNAcase, exhibited enhanced retinal protein O-GlcNAcylation and increased Cd40 mRNA tran...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Sadie K. Dierschke, Allyson L. Toro, William P. Miller, Siddharth Sunilkumar, Michael D. Dennis Tags: Molecular Bases of Disease Source Type: research

The orphan receptor GPR139 signals via Gq/11 to oppose opioid effects [Neurobiology]
In this study, we report that GPR139 activates multiple heterotrimeric G proteins, including members of the Gq/11 and Gi/o families. Using a panel of reporter assays in reconstituted HEK293T/17 cells, we found that GPR139 functions via the Gq/11 pathway and thereby distinctly regulates cellular effector systems, including stimulation of cAMP production and inhibition of G protein inward rectifying potassium (GIRK) channels. Electrophysiological recordings from medial habenular neurons revealed that GPR139 signaling via Gq/11 is necessary and sufficient for counteracting MOR-mediated inhibition of neuronal firing. These res...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Hannah M. Stoveken, Stefano Zucca, Ikuo Masuho, Brock Grill, Kirill A. Martemyanov Tags: Accelerated Communications Source Type: research

A myelin basic protein fragment induces sexually dimorphic transcriptome signatures of neuropathic pain in mice [Gene Regulation]
In the peripheral nerve, mechanosensitive axons are insulated by myelin, a multilamellar membrane formed by Schwann cells. Here, we offer first evidence that a myelin degradation product induces mechanical hypersensitivity and global transcriptomics changes in a sex-specific manner. Focusing on downstream signaling events of the functionally active 84-104 myelin basic protein (MBP(84-104)) fragment released after nerve injury, we demonstrate that exposing the sciatic nerve to MBP(84-104) via endoneurial injection produces robust mechanical hypersensitivity in female, but not in male, mice. RNA-seq and systems biology analy...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Andrei V. Chernov, Swathi K. Hullugundi, Kelly A. Eddinger, Jennifer Dolkas, Albert G. Remacle, Mila Angert, Brian P. James, Tony L. Yaksh, Alex Y. Strongin, Veronica I. Shubayev Tags: Neurobiology Source Type: research

The J-elongated conformation of {beta}2-glycoprotein I predominates in solution: implications for our understanding of antiphospholipid syndrome [Immunology]
β2-Glycoprotein I (β2GPI) is an abundant plasma protein displaying phospholipid-binding properties. Because it binds phospholipids, it is a target of antiphospholipid antibodies (aPLs) in antiphospholipid syndrome (APS), a life-threatening autoimmune thrombotic disease. Indeed, aPLs prefer membrane-bound β2GPI to that in solution. β2GPI exists in two almost equally populated redox states: oxidized, in which all the disulfide bonds are formed, and reduced, in which one or more disulfide bonds are broken. Furthermore, β2GPI can adopt multiple conformations (i.e. J-elongated, S-twisted, and O-circular...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Eliza Ruben, William Planer, Mathivanan Chinnaraj, Zhiwei Chen, Xiaobing Zuo, Vittorio Pengo, Vincenzo De Filippis, Ravi K. Alluri, Keith R. McCrae, Paolo Macor, Francesco Tedesco, Nicola Pozzi Tags: Protein Structure and Folding Source Type: research

Two clusters of surface-exposed amino acid residues enable high-affinity binding of retinal degeneration-3 (RD3) protein to retinal guanylyl cyclase [Neurobiology]
Retinal degeneration-3 (RD3) protein protects photoreceptors from degeneration by preventing retinal guanylyl cyclase (RetGC) activation via calcium-sensing guanylyl cyclase–activating proteins (GCAP), and RD3 truncation causes severe congenital blindness in humans and other animals. The three-dimensional structure of RD3 has recently been established, but the molecular mechanisms of its inhibitory binding to RetGC remain unclear. Here, we report the results of probing 133 surface-exposed residues in RD3 by single substitutions and deletions to identify side chains that are critical for the inhibitory binding of RD3 ...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Igor V. Peshenko, Alexander M. Dizhoor Tags: Signal Transduction Source Type: research

Cross-utilization of {beta}-galactosides and cellobiose in Geobacillus stearothermophilus [Enzymology]
Strains of the Gram-positive, thermophilic bacterium Geobacillus stearothermophilus possess elaborate systems for the utilization of hemicellulolytic polysaccharides, including xylan, arabinan, and galactan. These systems have been studied extensively in strains T-1 and T-6, representing microbial models for the utilization of soil polysaccharides, and many of their components have been characterized both biochemically and structurally. Here, we characterized routes by which G. stearothermophilus utilizes mono- and disaccharides such as galactose, cellobiose, lactose, and galactosyl-glycerol. The G. stearothermophilus geno...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Smadar Shulami, Arie Zehavi, Valery Belakhov, Rachel Salama, Shifra Lansky, Timor Baasov, Gil Shoham, Yuval Shoham Tags: Microbiology Source Type: research

A-kinase-anchoring protein 1 (dAKAP1)-based signaling complexes coordinate local protein synthesis at the mitochondrial surface [Cell Biology]
Compartmentalization of macromolecules is a ubiquitous molecular mechanism that drives numerous cellular functions. The appropriate organization of enzymes in space and time enables the precise transmission and integration of intracellular signals. Molecular scaffolds constrain signaling enzymes to influence the regional modulation of these physiological processes. Mitochondrial targeting of protein kinases and protein phosphatases provides a means to locally control the phosphorylation status and action of proteins on the surface of this organelle. Dual-specificity protein kinase A anchoring protein 1 (dAKAP1) is a multiv...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Laura Gabrovsek, Kerrie B. Collins, Stacey Aggarwal, Lauren M. Saunders, Ho-Tak Lau, Danny Suh, Yasemin Sancak, Cole Trapnell, Shao-En Ong, F. Donelson Smith, John D. Scott Tags: Signal Transduction Source Type: research

Structural and functional conservation of the programmed -1 ribosomal frameshift signal of SARS coronavirus 2 (SARS-CoV-2) [Gene Regulation]
Approximately 17 years after the severe acute respiratory syndrome coronavirus (SARS-CoV) epidemic, the world is currently facing the COVID-19 pandemic caused by SARS corona virus 2 (SARS-CoV-2). According to the most optimistic projections, it will take more than a year to develop a vaccine, so the best short-term strategy may lie in identifying virus-specific targets for small molecule–based interventions. All coronaviruses utilize a molecular mechanism called programmed −1 ribosomal frameshift (−1 PRF) to control the relative expression of their proteins. Previous analyses of SARS-CoV have revealed tha...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Jamie A. Kelly, Alexandra N. Olson, Krishna Neupane, Sneha Munshi, Josue San Emeterio, Lois Pollack, Michael T. Woodside, Jonathan D. Dinman Tags: Accelerated Communications Source Type: research

Mediator complex subunit 16 is down-regulated in papillary thyroid cancer, leading to increased transforming growth factor-{beta} signaling and radioiodine resistance [Signal Transduction]
In conclusion, our findings indicate that MED16 reduction in PTC contributes to tumor progression and RAI resistance via the activation of the TGF-β pathway. (Source: Journal of Biological Chemistry)
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Hongwei Gao, Peirong Bai, Lin Xiao, Mengjia Shen, Qiuxiao Yu, Yuanyuan Lei, Wenting Huang, Xiang Lin, Xinyi Zheng, Tao Wei, Yong Jiang, Feng Ye, Hong Bu Tags: Molecular Bases of Disease Source Type: research

Two bacterial glycosphingolipid synthases responsible for the synthesis of glucuronosylceramide and {alpha}-galactosylceramide [Lipids]
Bacterial glycosphingolipids such as glucuronosylceramide and galactosylceramide have been identified as ligands for invariant natural killer T cells and play important roles in host defense. However, the glycosphingolipid synthases required for production of these ceramides have not been well-characterized. Here, we report the identification and characterization of glucuronosylceramide synthase (ceramide UDP-glucuronosyltransferase [Cer-GlcAT]) in Zymomonas mobilis, a Gram-negative bacterium whose cellular membranes contain glucuronosylceramide. On comparing the gene sequences that encode the diacylglycerol GlcAT in bacte...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Nozomu Okino, Mengbai Li, Qingjun Qu, Tomoko Nakagawa, Yasuhiro Hayashi, Mitsufumi Matsumoto, Yohei Ishibashi, Makoto Ito Tags: Glycobiology and Extracellular Matrices Source Type: research

Post-translational modifications of Hsp70 family proteins: Expanding the chaperone code [Signal Transduction]
Cells must be able to cope with the challenge of folding newly synthesized proteins and refolding those that have become misfolded in the context of a crowded cytosol. One such coping mechanism that has appeared during evolution is the expression of well-conserved molecular chaperones, such as those that are part of the heat shock protein 70 (Hsp70) family of proteins that bind and fold a large proportion of the proteome. Although Hsp70 family chaperones have been extensively examined for the last 50 years, most studies have focused on regulation of Hsp70 activities by altered transcription, co-chaperone “helper&rdqu...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Nitika, Corey M. Porter, Andrew W. Truman, Matthias C. Truttmann Tags: JBC Reviews Source Type: research

Phosphorylation of {alpha}-dystrobrevin is essential for {alpha}kap accumulation and acetylcholine receptor stability [Protein Synthesis and Degradation]
The maintenance of a high density of the acetylcholine receptor (AChR) is the hallmark of the neuromuscular junction. Muscle-specific anchoring protein (αkap) encoded within the calcium/calmodulin-dependent protein kinase IIα (CAMK2A) gene is essential for the maintenance of AChR clusters both in vivo and in cultured muscle cells. The underlying mechanism by which αkap is maintained and regulated remains unknown. Here, using human cell lines, fluorescence microscopy, and pulldown and immunoblotting assays, we show that α-dystrobrevin (α-dbn), an intracellular component of the dystrophin glycop...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Po-Ju Chen, Diego Zelada, Dina Cheryne Belhasan, Mohammed Akaaboune Tags: Neurobiology Source Type: research

Crystal structure of a conformational antibody that binds tau oligomers and inhibits pathological seeding by extracts from donors with Alzheimer's disease [Protein Structure and Folding]
Soluble oligomers of aggregated tau accompany the accumulation of insoluble amyloid fibrils, a histological hallmark of Alzheimer disease (AD) and two dozen related neurodegenerative diseases. Both oligomers and fibrils seed the spread of Tau pathology, and by virtue of their low molecular weight and relative solubility, oligomers may be particularly pernicious seeds. Here, we report the formation of in vitro tau oligomers formed by an ionic liquid (IL15). Using IL15-induced recombinant tau oligomers and a dot blot assay, we discovered a mAb (M204) that binds oligomeric tau, but not tau monomers or fibrils. M204 and an eng...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Romany Abskharon, Paul M. Seidler, Michael R. Sawaya, Duilio Cascio, Tianxiao P. Yang, Stephan Philipp, Christopher Kazu Williams, Kathy L. Newell, Bernardino Ghetti, Michael A. DeTure, Dennis W. Dickson, Harry V. Vinters, Philip L. Felgner, Rie Nakajima, Tags: Molecular Bases of Disease Source Type: research

A revolution in biochemistry and molecular biology education informed by basic research to meet the demands of 21st century career paths [Methods and Resources]
The National Science Foundation estimates that 80% of the jobs available during the next decade will require math and science skills, dictating that programs in biochemistry and molecular biology must be transformative and use new pedagogical approaches and experiential learning for careers in industry, research, education, engineering, health-care professions, and other interdisciplinary fields. These efforts require an environment that values the individual student and integrates recent advances from the primary literature in the discipline, experimentally directed research, data collection and analysis, and scientific w...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Paul N. Black Tags: ASBMB Award Articles Source Type: research

A unique combination of glycoside hydrolases in Streptococcus suis specifically and sequentially acts on host-derived {alpha}Gal-epitope glycans [Enzymology]
Infections by many bacterial pathogens rely on their ability to degrade host glycans by producing glycoside hydrolases (GHs). Here, we discovered a conserved multifunctional GH, SsGalNagA, containing a unique combination of two family 32 carbohydrate-binding modules (CBM), a GH16 domain and a GH20 domain, in the zoonotic pathogen Streptococcus suis 05ZYH33. Enzymatic assays revealed that the SsCBM-GH16 domain displays endo-(β1,4)-galactosidase activity specifically toward the host-derived αGal epitope Gal(α1,3)Gal(β1,4)Glc(NAc)-R, whereas the SsGH20 domain has a wide spectrum of exo-β-N-acetylhex...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Ping Chen, Ran Liu, Mengmeng Huang, Jinlu Zhu, Dong Wei, Francis J. Castellino, Guanghui Dang, Fang Xie, Gang Li, Ziyin Cui, Siguo Liu, Yueling Zhang Tags: Enzymology Source Type: research

Picornaviral polymerase domain exchanges reveal a modular basis for distinct biochemical activities of viral RNA-dependent RNA polymerases [Molecular Bases of Disease]
Picornaviral RNA-dependent RNA polymerases (RdRPs) have low replication fidelity that is essential for viral fitness and evolution. Their global fold consists of the classical “cupped right hand” structure with palm, fingers, and thumb domains, and these RdRPs also possess a unique contact between the fingers and thumb domains. This interaction restricts movements of the fingers, and RdRPs use a subtle conformational change within the palm domain to close their active sites for catalysis. We have previously shown that this core RdRP structure and mechanism provide a platform for polymerases to fine-tune replica...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Colleen L. Watkins, Brian J. Kempf, Stephanie Beaucourt, David J. Barton, Olve B. Peersen Tags: Protein Structure and Folding Source Type: research

Prochlorococcus phage ferredoxin: structural characterization and electron transfer to cyanobacterial sulfite reductases [Protein Structure and Folding]
Marine cyanobacteria are infected by phages whose genomes encode ferredoxin (Fd) electron carriers. These Fds are thought to redirect the energy harvested from light to phage-encoded oxidoreductases that enhance viral fitness, but it is unclear how the biophysical properties and partner specificities of phage Fds relate to those of photosynthetic organisms. Here, results of a bioinformatics analysis using a sequence similarity network revealed that phage Fds are most closely related to cyanobacterial Fds that transfer electrons from photosystems to oxidoreductases involved in nutrient assimilation. Structural analysis of m...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Ian J. Campbell, Jose Luis Olmos Jr., Weijun Xu, Dimithree Kahanda, Joshua T. Atkinson, Othneil Noble Sparks, Mitchell D. Miller, George N. Phillips Jr., George N. Bennett, Jonathan J. Silberg Tags: Bioenergetics Source Type: research

Lipopolysaccharide O-antigens—bacterial glycans made to measure [Glycobiology and Extracellular Matrices]
Lipopolysaccharides are critical components of bacterial outer membranes. The more conserved lipid A part of the lipopolysaccharide molecule is a major element in the permeability barrier imposed by the outer membrane and offers a pathogen-associated molecular pattern recognized by innate immune systems. In contrast, the long-chain O-antigen polysaccharide (O-PS) shows remarkable structural diversity and fulfills a range of functions, depending on bacterial lifestyles. O-PS production is vital for the success of clinically important Gram-negative pathogens. The biological properties and functions of O-PSs are mostly indepe...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Chris Whitfield, Danielle M. Williams, Steven D. Kelly Tags: JBC Reviews Source Type: research

Golgi-localized exo-{beta}1,3-galactosidases involved in cell expansion and root growth in Arabidopsis [Glycobiology and Extracellular Matrices]
Plant arabinogalactan proteins (AGPs) are a diverse group of cell surface– and wall–associated glycoproteins. Functionally important AGP glycans are synthesized in the Golgi apparatus, but the relationships among their glycosylation levels, processing, and functionalities are poorly understood. Here, we report the identification and functional characterization of two Golgi-localized exo-β-1,3-galactosidases from the glycosyl hydrolase 43 (GH43) family in Arabidopsis thaliana. GH43 loss-of-function mutants exhibited root cell expansion defects in sugar-containing growth media. This root phenotype was associ...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Pieter Nibbering, Bent L. Petersen, Mohammed Saddik Motawia, Bodil Jorgensen, Peter Ulvskov, Totte Niittyla Tags: Plant Biology Source Type: research

Mechanical stretching changes crosslinking and glycation levels in the collagen of mouse tail tendon [Glycobiology and Extracellular Matrices]
Collagen I is a major tendon protein whose polypeptide chains are linked by covalent crosslinks. It is unknown how the crosslinking contributes to the mechanical properties of tendon or whether crosslinking changes in response to stretching or relaxation. Since their discovery, imine bonds within collagen have been recognized as being important in both crosslink formation and collagen structure. They are often described as acidic or thermally labile, but no evidence is available from direct measurements of crosslink levels whether these bonds contribute to the mechanical properties of collagen. Here, we used MS to analyze ...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Melanie Stammers, Izabella S. Niewczas, Anne Segonds-Pichon, Jonathan Clark Tags: Glycobiology and Extracellular Matrices Source Type: research

Age-related changes in the physical properties, cross-linking, and glycation of collagen from mouse tail tendon [Glycobiology and Extracellular Matrices]
Collagen is a structural protein whose internal cross-linking critically determines the properties and functions of connective tissue. Knowing how the cross-linking of collagen changes with age is key to understanding why the mechanical properties of tissues change over a lifetime. The current scientific consensus is that collagen cross-linking increases with age and that this increase leads to tendon stiffening. Here, we show that this view should be reconsidered. Using MS-based analyses, we demonstrated that during aging of healthy C57BL/6 mice, the overall levels of collagen cross-linking in tail tendon decreased with a...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Melanie Stammers, Irina M. Ivanova, Izabella S. Niewczas, Anne Segonds-Pichon, Matthew Streeter, David A. Spiegel, Jonathan Clark Tags: Glycobiology and Extracellular Matrices Source Type: research

The adaptor protein SHCA launches cancer invasion [Cell Biology]
Cancer cell invasion and metastasis rely on invadopodia, important extensions of the cytoskeleton that initiate degradation of the basement membrane that holds a cell in place. Transforming growth factor-β (TGF-β) is well-known to induce breast cancer migration and invasion, but the mechanism by which TGF-β signaling converts into cell motility is not completely understood. A study from Kiepas et al. revealed a new TGF-β–dependent role for Src homology/collagen adaptor protein (SHCA) in the initiation of dynamic adhesion complexes involved in the formation of invadopodia. These results highlight n...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Supriya Borah, Neil A. Bhowmick Tags: Editors ' Picks Highlights Source Type: research

The SHCA adapter protein cooperates with lipoma-preferred partner in the regulation of adhesion dynamics and invadopodia formation [Cell Biology]
SHC adaptor protein (SHCA) and lipoma-preferred partner (LPP) mediate transforming growth factor β (TGFβ)-induced breast cancer cell migration and invasion. Reduced expression of either protein diminishes breast cancer lung metastasis, but the reason for this effect is unclear. Here, using total internal reflection fluorescence (TIRF) microscopy, we found that TGFβ enhanced the assembly and disassembly rates of paxillin-containing adhesions in an SHCA-dependent manner through the phosphorylation of the specific SHCA tyrosine residues Tyr-239, Tyr-240, and Tyr-313. Using a BioID proximity labeling approach, w...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Alex Kiepas, Elena Voorand, Julien Senecal, Ryuhȷin Ahn, Matthew G. Annis, Kevin Jacquet, George Tali, Nicolas Bisson, Josie Ursini–Siegel, Peter M. Siegel, Claire M. Brown Tags: Editors ' Picks Source Type: research

CobT and BzaC catalyze the regiospecific activation and methylation of the 5-hydroxybenzimidazole lower ligand in anaerobic cobamide biosynthesis [Metabolism]
In conclusion, we validate MtBzaC as a SAM:hydroxybenzimidazole-riboside methyltransferase (HBIR-OMT). Finally, we propose a new pathway for the synthesis and activation of the benzimidazolyl lower ligand in anaerobic cobamide biosynthesis. (Source: Journal of Biological Chemistry)
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Yamini Mathur, Sheryl Sreyas, Prathamesh M. Datar, Manjima B. Sathian, Amrita B. Hazra Tags: Editors ' Picks Source Type: research

The GTPase-activating protein p120RasGAP has an evolutionarily conserved “FLVR-unique” SH2 domain [Molecular Biophysics]
The Src homology 2 (SH2) domain has a highly conserved architecture that recognizes linear phosphotyrosine motifs and is present in a wide range of signaling pathways across different evolutionary taxa. A hallmark of SH2 domains is the arginine residue in the conserved FLVR motif that forms a direct salt bridge with bound phosphotyrosine. Here, we solve the X-ray crystal structures of the C-terminal SH2 domain of p120RasGAP (RASA1) in its apo and peptide-bound form. We find that the arginine residue in the FLVR motif does not directly contact pTyr1087 of a bound phosphopeptide derived from p190RhoGAP; rather, it makes an i...
Source: Journal of Biological Chemistry - July 31, 2020 Category: Chemistry Authors: Rachel Jaber Chehayeb, Jessica Wang, Amy L. Stiegler, Titus J. Boggon Tags: Editors ' Picks Source Type: research

Correction: Caveolin-1 inhibits expression of antioxidant enzymes through direct interaction with nuclear erythroid 2 p45-related factor-2 (Nrf2). [Additions and Corrections]
VOLUME 287 (2012) PAGES 20922–20930The immunoblot of β-actin in Fig. 1C was inadvertently duplicated from another publication. This error has now been corrected using the original data and does not affect the results or the conclusions of this work. Augustine M.K. Choi should be removed as an author. The corrected author list is shown above.jbc;295/30/10510/F1F1F1Figure 1. (Source: Journal of Biological Chemistry)
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Wen Li, Hui Liu, Jie-Sen Zhou, Jiao-Fei Cao, Xiao-Bo Zhou, Zhi-Hua Chen, Hua-Hao Shen Tags: Additions and Corrections Source Type: research

Correction: A novel CXCR3-B chemokine receptor-induced growth-inhibitory signal in cancer cells is mediated through the regulation of Bach-1 protein and Nrf2 protein nuclear translocation. [Additions and Corrections]
VOLUME 289 (2014) PAGES 3126–3137There was an error in Fig 6C. The dot plot in panel 1 (Control siRNA + Vector) was mistakenly duplicated with the dot plot in panel 4 (Bach-1 siRNA + CXCR3-B). However, the numbers of the % apoptotic cells were correct. This error happened inadvertently during the preparation of the figure panels. This error has now been corrected and does not affect the results or conclusions of the work reported in this study. The authors apologize for this error.jbc;295/30/10509/F6F1F6Figure 6. (Source: Journal of Biological Chemistry)
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Murugabaskar Balan, Soumitro Pal Tags: Additions and Corrections Source Type: research

Correction: Hepatic heparan sulfate is a master regulator of hepcidin expression and iron homeostasis in human hepatocytes and mice. [Additions and Corrections]
VOLUME 294 (2019) PAGES 13292–13303There were two minor errors. The last sentence in the figure legend of Fig. 2 should read, “The data were analyzed using one-way ANOVA and an uncorrected Student's t test.” In Fig. 3D, the p values between the fourth, fifth, and sixth histograms were incorrect due to an error made in transferring information from Prism. These errors have now been corrected and do not affect the results or conclusions of this work.jbc;295/30/10508/F3F1F3Figure 3D. (Source: Journal of Biological Chemistry)
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Maura Poli, Ferdous Anower-E-Khuda, Michela Asperti, Paola Ruzzenenti, Magdalena Gryzik, Andrea Denardo, Philip L. S. M. Gordts, Paolo Arosio, Jeffrey D. Esko Tags: Additions and Corrections Source Type: research

Reply to Rutter et al.: The roles of cytosolic and intramitochondrial Ca2+ and the mitochondrial Ca2+-uniporter (MCU) in the stimulation of mammalian oxidative phosphorylation [Letters to the Editor]
Each model used in the work referred to by Rutter et al. (1) addressed certain aspects of mitochondrial biology, and together, they fully support the conclusions made. Please note that we describe Ca2+-mediated regulation of oxidative phosphorylation (OXPHOS) fluxes (2, 3) and do not question Ca2+-responsiveness of pyruvate dehydrogenase en-zyme activity (4). To address concerns such as those raised by Rutter et al. (1), we studied glutamate/malate-dependent OXPHOS in the absence of exogenous pyruvate in mitochondria, omitted pyruvate from cell experiments, and implemented the working rat heart model perfused by Krebs&ndas...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Frank N. Gellerich, Marten Szibor, Zemfira Gizatullina, Volkmar Lessmann, Michael Schwarzer, Torsten Doenst, Stefan Vielhaber, Wolfram S. Kunz Tags: Letters to the Editor Source Type: research

The roles of cytosolic and intramitochondrial Ca2+ and the mitochondrial Ca2+-uniporter (MCU) in the stimulation of mammalian oxidative phosphorylation [Letters to the Editor]
Szibor et al. (1) concluded that mitochondrial pyruvate oxidation is regulated primarily by cytosolic Ca2+ ([Ca2+]cyt) activation of the malate-aspartate shuttle, rather than by mitochondrial Ca2+ ([Ca2+]mit) activation of intramitochondrial dehydrogenases. Pyruvate dehydrogenase (PDH) activity largely reflects the ratio of active nonphosphorylated PDH to inactive phosphorylated PDH (PDHP) (2), but Szibor et al. (1) did not measure PDH/PDHP ratios. Moreover, their studies used unphysiological conditions with isolated mitochondria (saturating ADP); with synaptosomes, thymocytes, and fibroblasts (uncoupler and high pyruvate)...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Guy A. Rutter, James G. McCormack, Andrew P. Halestrap, Richard M. Denton Tags: Letters to the Editor Source Type: research

Oxygen battle in the gut: Hypoxia and hypoxia-inducible factors in metabolic and inflammatory responses in the intestine [Gene Regulation]
The gastrointestinal tract is a highly proliferative and regenerative tissue. The intestine also harbors a large and diverse microbial population collectively called the gut microbiome (microbiota). The microbiome–intestine cross-talk includes a dynamic exchange of gaseous signaling mediators generated by bacterial and intestinal metabolisms. Moreover, the microbiome initiates and maintains the hypoxic environment of the intestine that is critical for nutrient absorption, intestinal barrier function, and innate and adaptive immune responses in the mucosal cells of the intestine. The response to hypoxia is mediated by...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Rashi Singhal, Yatrik M. Shah Tags: JBC Reviews Source Type: research

Deciphering site 3 interactions of interleukin 12 and interleukin 23 with their cognate murine and human receptors [Signal Transduction]
Interleukin (IL)–12 and IL-23 belong to the IL-12 type family and are composite cytokines, consisting of the common β subunit p40 and the specific cytokine α subunit p35 and p19, respectively. IL-12 signals via the IL-12Rβ1·IL-12Rβ2 receptor complex, and IL-23 uses also IL-12Rβ1 but engages IL-23R as second receptor. Importantly, binding of IL-12 and IL-23 to IL-12Rβ1 is mediated by p40, and binding to IL-12Rβ2 and IL-23R is mediated by p35 and p19, respectively. Previously, we have identified a W157A substitution at site 3 of murine IL-23p19 that abrogates binding to murine...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Alessandra Esch, Anna Masiarz, Sofie Mossner, Jens M. Moll, Joachim Grotzinger, Jutta Schroder, Jurgen Scheller, Doreen M. Floss Tags: Signal Transduction Source Type: research

A single von Willebrand factor C-domain protein acts as an extracellular pattern-recognition receptor in the river prawn Macrobrachium nipponense [Cell Biology]
The single von Willebrand factor C-domain proteins (SVWCs) are mainly found in arthropods. Their expression may be regulated by several environmental stresses, including nutritional status and bacterial and viral infections. However, the underlying regulatory mechanism is unclear. In the present study, we identified a member of the SVWC family from the river prawn Macrobrachium nipponense as a soluble and bacteria-inducible pattern-recognition receptor (designated MnSVWC). In vitro, recombinant MnSVWC exhibited pronounced binding and Ca2+-dependent agglutinating abilities against diverse microbes, including Gram-negative b...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Nan Qin, Hehe Sun, Meike Lu, Jianhui Wang, Ting Tang, Fengsong Liu Tags: Immunology Source Type: research

Contributions of the heme coordinating ligands of the Pseudomonas aeruginosa outer membrane receptor HasR to extracellular heme sensing and transport [Signal Transduction]
Pseudomonas aeruginosa exhibits a high requirement for iron, which it can acquire via several mechanisms, including the acquisition and utilization of heme. The P. aeruginosa genome encodes two heme uptake systems, the heme assimilation system (Has) and the Pseudomonas heme utilization (Phu) system. Extracellular heme is sensed via the Has system, which encodes an extracytoplasmic function (ECF) σ factor system. Previous studies have shown that the transfer of heme from the extracellular hemophore HasAp to the outer membrane receptor HasR is required for activation of the σ factor HasI and upregulation of has o...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Alecia T. Dent, Angela Wilks Tags: Microbiology Source Type: research

The serum protein transthyretin as a platform for dimerization and tetramerization of antibodies and Fab fragments to enable target clustering [Protein Structure and Folding]
Transthyretin (TTR) is an abundant homotetrameric serum protein and was selected here for engineering higher-valency molecules because of its compact size, simple structure, and natural propensity to tetramerize. To demonstrate this utility, we fused TTR to the C terminus of conatumumab, an antibody that targets tumor necrosis factor–related apoptosis-inducing ligand receptor 2, as heavy chains to form antibody dimers and Fab heavy chains to form Fab tetramers. Moreover, we used constant heavy domain 3 heterodimerization substitutions to create TTR-mediated conatumumab tetramers. The conatumumab–TTR fusions dis...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Kenneth W. Walker, Ian N. Foltz, Tina Wang, Hossein Salimi-Moosavi, Julie M. Bailis, Fei Lee, Phillip An, Stephen Smith, Richele Bruno, Zhulun Wang Tags: Protein Structure and Folding Source Type: research

Translational regulation of environmental adaptation in bacteria [Microbiology]
Bacteria must rapidly respond to both intracellular and environmental changes to survive. One critical mechanism to rapidly detect and adapt to changes in environmental conditions is control of gene expression at the level of protein synthesis. At each of the three major steps of translation—initiation, elongation, and termination—cells use stimuli to tune translation rate and cellular protein concentrations. For example, changes in nutrient concentrations in the cell can lead to translational responses involving mechanisms such as dynamic folding of riboswitches during translation initiation or the synthesis o...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Rodney Tollerson II, Michael Ibba Tags: JBC Reviews Source Type: research

Incomplete glycosylation during prion infection unmasks a prion protein epitope that facilitates prion detection and strain discrimination [Cell Biology]
The causative factors underlying conformational conversion of cellular prion protein (PrPC) into its infectious counterpart (PrPSc) during prion infection remain undetermined, in part because of a lack of monoclonal antibodies (mAbs) that can distinguish these conformational isoforms. Here we show that the anti-PrP mAb PRC7 recognizes an epitope that is shielded from detection when glycans are attached to Asn-196. We observed that whereas PrPC is predisposed to full glycosylation and is therefore refractory to PRC7 detection, prion infection leads to diminished PrPSc glycosylation at Asn-196, resulting in an unshielded PRC...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Hae-Eun Kang, Jifeng Bian, Sarah J. Kane, Sehun Kim, Vanessa Selwyn, Jenna Crowell, Jason C. Bartz, Glenn C. Telling Tags: Molecular Bases of Disease Source Type: research

The ER-associated protease Ste24 prevents N-terminal signal peptide-independent translocation into the endoplasmic reticulum in Saccharomyces cerevisiae [Glycobiology and Extracellular Matrices]
Soluble proteins destined for the secretory pathway contain an N-terminal signal peptide that induces their translocation into the endoplasmic reticulum (ER). The importance of N-terminal signal peptides for ER translocation has been extensively examined over the past few decades. However, in the budding yeast Saccharomyces cerevisiae, a few proteins devoid of a signal peptide are still translocated into the ER and then N-glycosyl-ated. Using signal peptide-truncated reporter proteins, here we report the detection of significant translocation of N-terminal signal peptide-truncated proteins in a yeast mutant strain (ste24&D...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Akira Hosomi, Kazuko Iida, Toshihiko Cho, Hidetoshi Iida, Masashi Kaneko, Tadashi Suzuki Tags: Cell Biology Source Type: research

A substitution in cGMP-dependent protein kinase 1 associated with aortic disease induces an active conformation in the absence of cGMP [Molecular Bases of Disease]
Type 1 cGMP-dependent protein kinases (PKGs) play important roles in human cardiovascular physiology, regulating vascular tone and smooth-muscle cell phenotype. A mutation in the human PRKG1 gene encoding cGMP-dependent protein kinase 1 (PKG1) leads to thoracic aortic aneurysms and dissections. The mutation causes an arginine-to-glutamine (RQ) substitution within the first cGMP-binding pocket in PKG1. This substitution disrupts cGMP binding to the pocket, but it also unexpectedly causes PKG1 to have high activity in the absence of cGMP via an unknown mechanism. Here, we identified the molecular mechanism whereby the RQ mut...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Matthew H. Chan, Sahar Aminzai, Tingfei Hu, Amatya Taran, Sheng Li, Choel Kim, Renate B. Pilz, Darren E. Casteel Tags: Protein Structure and Folding Source Type: research

Sodium channel {beta}1 subunits are post-translationally modified by tyrosine phosphorylation, S-palmitoylation, and regulated intramembrane proteolysis [Cell Biology]
Voltage-gated sodium channel (VGSC) β1 subunits are multifunctional proteins that modulate the biophysical properties and cell-surface localization of VGSC α subunits and participate in cell–cell and cell–matrix adhesion, all with important implications for intracellular signal transduction, cell migration, and differentiation. Human loss-of-function variants in SCN1B, the gene encoding the VGSC β1 subunits, are linked to severe diseases with high risk for sudden death, including epileptic encephalopathy and cardiac arrhythmia. We showed previously that β1 subunits are post-translationally ...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Alexandra A. Bouza, Julie M. Philippe, Nnamdi Edokobi, Alexa M. Pinsky, James Offord, Jeffrey D. Calhoun, Mariana Lopez–Floran, Luis F. Lopez–Santiago, Paul M. Jenkins, Lori L. Isom Tags: Neurobiology Source Type: research

Two components of DNA replication-dependent LexA cleavage [Gene Regulation]
Induction of the SOS response, a cellular system triggered by DNA damage in bacteria, depends on DNA replication for the generation of the SOS signal, ssDNA. RecA binds to ssDNA, forming filaments that stimulate proteolytic cleavage of the LexA transcriptional repressor, allowing expression of> 40 gene products involved in DNA repair and cell cycle regulation. Here, using a DNA replication system reconstituted in vitro in tandem with a LexA cleavage assay, we studied LexA cleavage during DNA replication of both undamaged and base-damaged templates. Only a ssDNA–RecA filament supported LexA cleavage. Surprisingly, ...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Kamila K. Myka, Kenneth J. Marians Tags: DNA and Chromosomes Source Type: research

Role of the lipid bilayer in outer membrane protein folding in Gram-negative bacteria [Molecular Biophysics]
β-Barrel outer membrane proteins (OMPs) represent the major proteinaceous component of the outer membrane (OM) of Gram-negative bacteria. These proteins perform key roles in cell structure and morphology, nutrient acquisition, colonization and invasion, and protection against external toxic threats such as antibiotics. To become functional, OMPs must fold and insert into a crowded and asymmetric OM that lacks much freely accessible lipid. This feat is accomplished in the absence of an external energy source and is thought to be driven by the high thermodynamic stability of folded OMPs in the OM. With such a stable fol...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Jim E. Horne, David J. Brockwell, Sheena E. Radford Tags: JBC Reviews Source Type: research

Bi-allelic expression of the RyR1 p.A4329D mutation decreases muscle strength in slow-twitch muscles in mice [Molecular Bases of Disease]
Mutations in the ryanodine receptor 1 (RYR1) gene are associated with several human congenital myopathies, including the dominantly inherited central core disease and exercise-induced rhabdomyolysis, and the more severe recessive phenotypes, including multiminicore disease, centronuclear myopathy, and congenital fiber type disproportion. Within the latter group, those carrying a hypomorphic mutation in one allele and a missense mutation in the other are the most severely affected. Because of nonsense-mediated decay, most hypomorphic alleles are not expressed, resulting in homozygous expression of the missense mutation alle...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Moran Elbaz, Alexis Ruiz, Sven Nicolay, Chiara Tupini, Christoph Bachmann, Jan Eckhardt, Sofia Benucci, Pawel Pelczar, Susan Treves, Francesco Zorzato Tags: Molecular Bases of Disease Source Type: research

Mechanisms of evolved herbicide resistance [Plant Biology]
The widely successful use of synthetic herbicides over the past 70 years has imposed strong and widespread selection pressure, leading to the evolution of herbicide resistance in hundreds of weed species. Both target-site resistance (TSR) and nontarget-site resistance (NTSR) mechanisms have evolved to most herbicide classes. TSR often involves mutations in genes encoding the protein targets of herbicides, affecting the binding of the herbicide either at or near catalytic domains or in regions affecting access to them. Most of these mutations are nonsynonymous SNPs, but polymorphisms in more than one codon or entire codon d...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Todd A. Gaines, Stephen O. Duke, Sarah Morran, Carlos A. G. Rigon, Patrick J. Tranel, Anita Kupper, Franck E. Dayan Tags: JBC Reviews Source Type: research

A cellular endolysosome-modulating pore-forming protein from a toad is negatively regulated by its paralog under oxidizing conditions [Membrane Biology]
Endolysosomes are key players in cell physiology, including molecular exchange, immunity, and environmental adaptation. They are the molecular targets of some pore-forming aerolysin-like proteins (ALPs) that are widely distributed in animals and plants and are functionally related to bacterial toxin aerolysins. βγ-CAT is a complex of an ALP (BmALP1) and a trefoil factor (BmTFF3) in the firebelly toad (Bombina maxima). It is the first example of a secreted endogenous pore-forming protein that modulates the biochemical properties of endolysosomes by inducing pore formation in these intracellular vesicles. Here, us...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Qiquan Wang, Xianling Bian, Lin Zeng, Fei Pan, Lingzhen Liu, Jinyang Liang, Lingyan Wang, Kaifeng Zhou, Wenhui Lee, Yang Xiang, Sheng'an Li, Maikun Teng, Xu Li, Xiaolong Guo, Yun Zhang Tags: Gene Regulation Source Type: research

Suramin and NF449 are IP5K inhibitors that disrupt inositol hexakisphosphate-mediated regulation of cullin-RING ligase and sensitize cancer cells to MLN4924/pevonedistat [Protein Synthesis and Degradation]
Inositol hexakisphosphate (IP6) is an abundant metabolite synthesized from inositol 1,3,4,5,6-pentakisphosphate (IP5) by the single IP5 2-kinase (IP5K). Genetic and biochemical studies have shown that IP6 usually functions as a structural cofactor in protein(s) mediating mRNA export, DNA repair, necroptosis, 3D genome organization, HIV infection, and cullin–RING ligase (CRL) deneddylation. However, it remains unknown whether pharmacological perturbation of cellular IP6 levels affects any of these processes. Here, we performed screening for small molecules that regulate human IP5K activity, revealing that the antipara...
Source: Journal of Biological Chemistry - July 24, 2020 Category: Chemistry Authors: Xiaozhe Zhang, Shaodong Shi, Yang Su, Xiaoli Yang, Sining He, Xiuyan Yang, Jing Wu, Jian Zhang, Feng Rao Tags: Enzymology Source Type: research