Stoichiometry of the eIF2B complex is maintained by mutual stabilization of subunits
The eukaryotic translation initiation factor eIF2B is a multi-subunit complex with a crucial role in the regulation of global protein synthesis in the cell. The complex comprises five subunits, termed α through in order of increasing size, arranged as a heterodecamer with two copies of each subunit. Regulation of the co-stoichiometric expression of the eIF2B subunits is crucial for the proper function and regulation of the eIF2B complex in cells. We have investigated the control of stoichiometric eIF2B complexes through mutual stabilization of eIF2B subunits.  Our data show that the stable expression of the cata...
Source: Biochemical Journal - February 24, 2016 Category: Biochemistry Authors: Wortham, N. C., Stewart, J. D., Harris, S., Coldwell, M. J., Proud, C. G. Tags: Gene Research articles Source Type: research

Directed evolution of Tau class glutathione transferases reveals a site that regulates catalytic efficiency and masks co-operativity
A library of Tau class GSTs (glutathione transferases) was constructed by DNA shuffling using the DNA encoding the Glycine max GSTs GmGSTU2-2, GmGSTU4-4 and GmGSTU10-10. The parental GSTs are>88% identical at the sequence level; however, their specificity varies towards different substrates. The DNA library contained chimaeric structures of alternated segments of the parental sequences and point mutations. Chimaeric GST sequences were expressed in Escherichia coli and their enzymatic activities towards CDNB (1-chloro-2,4-dinitrobenzene) and the herbicide fluorodifen (4-nitrophenyl α,α,α-trifluoro-2-nit...
Source: Biochemical Journal - February 24, 2016 Category: Biochemistry Authors: Axarli, I., Muleta, A. W., Vlachakis, D., Kossida, S., Kotzia, G., Maltezos, A., Dhavala, P., Papageorgiou, A. C., Labrou, N. E. Tags: Biomolecules Research articles Source Type: research

Identification of novel members of the bacterial azoreductase family in Pseudomonas aeruginosa
Azoreductases are a family of diverse enzymes found in many pathogenic bacteria as well as distant homologues being present in eukarya. In addition to having azoreductase activity, these enzymes are also suggested to have NAD(P)H quinone oxidoreductase (NQO) activity which leads to a proposed role in plant pathogenesis. Azoreductases have also been suggested to play a role in the mammalian pathogenesis of Pseudomonas aeruginosa. In view of the importance of P. aeruginosa as a pathogen, we therefore characterized recombinant enzymes following expression of a group of putative azoreductase genes from P. aeruginosa expressed ...
Source: Biochemical Journal - February 24, 2016 Category: Biochemistry Authors: Crescente, V., Holland, S. M., Kashyap, S., Polycarpou, E., Sim, E., Ryan, A. Tags: Biomolecules Research articles Source Type: research

Soluble CD109 binds TGF-{beta} and antagonizes TGF-{beta} signalling and responses
Transforming growth factor-β (TGF-β) is a multifunctional cytokine implicated in many diseases, including tissue fibrosis and cancer. TGF-β mediates diverse biological responses by signalling through type I and II TGF-β receptors (TβRI and TβRII). We have previously identified CD109, a glycosylphosphatidylinositol (GPI)-anchored protein, as a novel TGF-β co-receptor that negatively regulates TGF-β signalling and responses and demonstrated that membrane-anchored CD109 promotes TGF-β receptor degradation via a SMAD7/Smurf2-mediated mechanism. To determine whether CD109 releas...
Source: Biochemical Journal - February 24, 2016 Category: Biochemistry Authors: Li, C., Hancock, M. A., Sehgal, P., Zhou, S., Reinhardt, D. P., Philip, A. Tags: Biomolecules Research articles Source Type: research

Taste information derived from T1R-expressing taste cells in mice
The taste system of animals is used to detect valuable nutrients and harmful compounds in foods. In humans and mice, sweet, bitter, salty, sour and umami tastes are considered the five basic taste qualities. Sweet and umami tastes are mediated by G-protein-coupled receptors, belonging to the T1R (taste receptor type 1) family. This family consists of three members (T1R1, T1R2 and T1R3). They function as sweet or umami taste receptors by forming heterodimeric complexes, T1R1+T1R3 (umami) or T1R2+T1R3 (sweet). Receptors for each of the basic tastes are thought to be expressed exclusively in taste bud cells. Sweet (T1R2+...
Source: Biochemical Journal - February 24, 2016 Category: Biochemistry Authors: Yoshida, R., Ninomiya, Y. Tags: Signalling Review articles Source Type: research

Protein kinase C{zeta} exhibits constitutive phosphorylation and phosphatidylinositol-3,4,5-triphosphate-independent regulation
Atypical protein kinase C (aPKC) isoenzymes are key modulators of insulin signalling, and their dysfunction correlates with insulin-resistant states in both mice and humans. Despite the engaged interest in the importance of aPKCs to type 2 diabetes, much less is known about the molecular mechanisms that govern their cellular functions than for the conventional and novel PKC isoenzymes and the functionally-related protein kinase B (Akt) family of kinases. Here we show that aPKC is constitutively phosphorylated and, using a genetically-encoded reporter for PKC activity, basally active in cells. Specifically, we show tha...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Tobias, I. S., Kaulich, M., Kim, P. K., Simon, N., Jacinto, E., Dowdy, S. F., King, C. C., Newton, A. C. Tags: Metabolism, Signalling Research articles Source Type: research

Determination of sites of U50,488H-promoted phosphorylation of the mouse {kappa} opioid receptor (KOPR): disconnect between KOPR phosphorylation and internalization
Phosphorylation sites of KOPR ( opioid receptor) following treatment with the selective agonist U50,488H {(–)(trans)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidiny)cyclo-hexyl]benzeneacetamide} were identified after affinity purification, SDS/PAGE, in-gel digestion with Glu-C and HPLC–MS/MS. Single- and double-phosphorylated peptides were identified containing phosphorylated Ser356, Thr357, Thr363 and Ser369 in the C-terminal domain. Antibodies were generated against three phosphopeptides containing pSer356/pThr357, pThr363 and pSer369 respectively, and affinity-purified antibodies were found to be highly specific f...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Chen, C., Chiu, Y.-T., Wu, W., Huang, P., Mann, A., Schulz, S., Liu-Chen, L.-Y. Tags: Biomolecules, ChemBio Research articles Source Type: research

Palmitate-induced impairment of glucose-stimulated insulin secretion precedes mitochondrial dysfunction in mouse pancreatic islets
It has been well established that excessive levels of glucose and palmitate lower glucose-stimulated insulin secretion (GSIS) by pancreatic β-cells. This β-cell ‘glucolipotoxicity’ is possibly mediated by mitochondrial dysfunction, but involvement of bioenergetic failure in the pathological mechanism is the subject of ongoing debate. We show in the present study that increased palmitate levels impair GSIS before altering mitochondrial function. We demonstrate that GSIS defects arise from increased insulin release under basal conditions in addition to decreased insulin secretion under glucose-stimulato...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Barlow, J., Jensen, V. H., Jastroch, M., Affourtit, C. Tags: Energy, Metabolism Research articles Source Type: research

Emodin inhibits coxsackievirus B3 replication via multiple signalling cascades leading to suppression of translation
CVB3 (coxsackievirus 3) is a primary causal agent of viral myocarditis. Emodin is a natural compound isolated from certain plant roots. In the present study, we found that emodin inhibited CVB3 replication in vitro and in mice, and now we report an unrecognized mechanism by which emodin inhibits CVB3 replication through suppression of viral protein translation via multiple pathways. On one hand, emodin treatment inhibited Akt/mTOR (mammalian target of rapamycin) signalling and activated 4EBP1 (eukaryotic initiation factor 4R-binding protein 1), leading to suppression of translation initiation of ribosomal protein L32 ...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Zhang, H. M., Wang, F., Qiu, Y., Ye, X., Hanson, P., Shen, H., Yang, D. Tags: Disease, Signalling Research articles Source Type: research

The crystal structure of an inverting glycoside hydrolase family 9 exo-{beta}-D-glucosaminidase and the design of glycosynthase
Exo-β-D-glucosaminidase (EC 3.2.1.165) from Photobacterium profundum (PpGlcNase) is an inverting GH (glycoside hydrolase) belonging to family 9. We have determined the three-dimensional structure of PpGlcNase to describe the first structure–function relationship of an exo-type GH9 glycosidase. PpGlcNase has a narrow and straight active-site pocket, in contrast with the long glycan-binding cleft of a GH9 endoglucanase. This is because PpGlcNase has a long loop, which blocks the position corresponding to subsites –4 to –2 of the endoglucanase. The pocket shape of PpGlcNase explains its substrate prefer...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Honda, Y., Arai, S., Suzuki, K., Kitaoka, M., Fushinobu, S. Tags: Biomolecules Research articles Source Type: research

The cancer-promoting gene fatty acid-binding protein 5 (FABP5) is epigenetically regulated during human prostate carcinogenesis
FABPs (fatty-acid-binding proteins) are a family of low-molecular-mass intracellular lipid-binding proteins consisting of ten isoforms. FABPs are involved in binding and storing hydrophobic ligands such as long-chain fatty acids, as well as transporting these ligands to the appropriate compartments in the cell. FABP5 is overexpressed in multiple types of tumours. Furthermore, up-regulation of FABP5 is strongly associated with poor survival in triple-negative breast cancer. However, the mechanisms underlying the specific up-regulation of the FABP5 gene in these cancers remain poorly characterized. In the present study,...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Kawaguchi, K., Kinameri, A., Suzuki, S., Senga, S., Ke, Y., Fujii, H. Tags: Disease, Gene Research articles Source Type: research

Calpain-controlled detachment of major glycoproteins from the cytoskeleton regulates adhesive properties of activated phosphatidylserine-positive platelets
In resting platelets, adhesive membrane glycoproteins are attached to the cytoskeleton. On strong activation, phosphatidylserine(PS)-positive and -negative platelet subpopulations are formed. Platelet activation is accompanied by cytoskeletal rearrangement, although the glycoprotein attachment status in these two subpopulations is not clear. We developed a new, flow cytometry-based, single-cell approach to investigate attachment of membrane glycoproteins to the cytoskeleton in cell subpopulations. In PS-negative platelets, adhesive glycoproteins integrin αIIbβ3, glycoprotein Ib and, as shown for the first time, ...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Artemenko, E. O., Yakimenko, A. O., Pichugin, A. V., Ataullakhanov, F. I., Panteleev, M. A. Tags: Cell, Signalling Research articles Source Type: research

Autism-associated R451C mutation in neuroligin3 leads to activation of the unfolded protein response in a PC12 Tet-On inducible system
Several forms of monogenic heritable autism spectrum disorders are associated with mutations in the neuroligin genes. The autism-linked substitution R451C in neuroligin3 induces local misfolding of its extracellular domain, causing partial retention in the ER (endoplasmic reticulum) of expressing cells. We have generated a PC12 Tet-On cell model system with inducible expression of wild-type or R451C neuroligin3 to investigate whether there is activation of the UPR (unfolded protein response) as a result of misfolded protein retention. As a positive control for protein misfolding, we also expressed the mutant G221R neurolig...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Ulbrich, L., Favaloro, F. L., Trobiani, L., Marchetti, V., Patel, V., Pascucci, T., Comoletti, D., Marciniak, S. J., De Jaco, A. Tags: Cell, Disease Research articles Source Type: research

Kinetic analysis of structural influences on the susceptibility of peroxiredoxins 2 and 3 to hyperoxidation
Mammalian 2-cysteine peroxiredoxins (Prxs) are susceptible to hyperoxidation by excess H2O2. The cytoplasmic family member Prx2 hyperoxidizes more readily than mitochondrial Prx3 due to slower dimerization of the sulfenic acid (SpOH) intermediate. Four variant amino acids near the C-terminus have been shown to contribute to this difference. We have performed kinetic analysis of the relationship between hyperoxidation and disulfide formation, using whole-protein MS and comparing wild-type (WT) Prx2 and Prx3 with tail-swap mutants in which the four amino acids were reversed. These changes make Prx3 more sensitive and Prx2 le...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Poynton, R. A., Peskin, A. V., Haynes, A. C., Lowther, W. T., Hampton, M. B., Winterbourn, C. C. Tags: Energy Research articles Source Type: research

A ternary complex comprising FAK, PTP{alpha} and IP3 receptor 1 functionally engages focal adhesions and the endoplasmic reticulum to mediate IL-1-induced Ca2+ signalling in fibroblasts
We examined the spatial restriction of Ca2+ release through the inositol 1,4,5-triphosphate receptor 1 (IP3R1) in response to interleukin-1 (IL-1) and the functions of the adhesion-associated proteins, focal adhesion kinase (FAK) and protein tyrosine phosphatase-α (PTPα). In cultured fibroblasts IL-1 treatment promoted co-localization of PTPα and FAK with the ER and increased association of IP3R1 with PTPα and FAK at focal adhesions (FAs). GST pull-down assays of purified proteins demonstrated that PTPα and FAK directly interacted with IP3R1. These interactions depended on the focal adhesion-t...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Wang, Q., Wang, Y., Downey, G. P., Plotnikov, S., McCulloch, C. A. Tags: Cell, Signalling Research articles Source Type: research

Actin polymerization is stimulated by actin cross-linking protein palladin
The actin scaffold protein palladin regulates both normal cell migration and invasive cell motility, processes that require the co-ordinated regulation of actin dynamics. However, the potential effect of palladin on actin dynamics has remained elusive. In the present study, we show that the actin-binding immunoglobulin-like domain of palladin, which is directly responsible for both actin binding and bundling, also stimulates actin polymerization in vitro. Palladin eliminated the lag phase that is characteristic of the slow nucleation step of actin polymerization. Furthermore, palladin dramatically reduced depolymeriza...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Gurung, R., Yadav, R., Brungardt, J. G., Orlova, A., Egelman, E. H., Beck, M. R. Tags: Cell, ChemBio Research articles Source Type: research

Inhibition of Wnt signalling and breast tumour growth by the multi-purpose drug suramin through suppression of heterotrimeric G proteins and Wnt endocytosis
Overactivation of the Wnt signalling pathway underlies oncogenic transformation and proliferation in many cancers, including the triple-negative breast cancer (TNBC), the deadliest form of tumour in the breast, taking about a quarter of a million lives annually worldwide. No clinically approved targeted therapies attacking Wnt signalling currently exist. Repositioning of approved drugs is a promising approach in drug discovery. In the present study we show that a multi-purpose drug suramin inhibits Wnt signalling and proliferation of TNBC cells in vitro and in mouse models, inhibiting a component in the upper levels o...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Koval, A., Ahmed, K., Katanaev, V. L. Tags: Signalling Research articles Source Type: research

The STAS domain of mammalian SLC26A5 prestin harbours an anion-binding site
Prestin is a unique ATP- and Ca2+-independent molecular motor with piezoelectric characteristics responsible for the electromotile properties of mammalian cochlear outer hair cells, i.e. the capacity of these cells to modify their length in response to electric stimuli. This ‘electromotility’ is at the basis of the exceptional sensitivity and frequency selectivity distinctive of mammals. Prestin belongs to the SLC26 (solute carrier 26) family of anion transporters and needs anions to function properly, particularly Cl–. In the present study, using X-ray crystallography we reveal that the STAS (sulfate tra...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Lolli, G., Pasqualetto, E., Costanzi, E., Bonetto, G., Battistutta, R. Tags: Biomolecules, ChemBio Accelerated Publications Source Type: research

New photosensitizers for photodynamic therapy
Photodynamic therapy (PDT) was discovered more than 100 years ago, and has since become a well-studied therapy for cancer and various non-malignant diseases including infections. PDT uses photosensitizers (PSs, non-toxic dyes) that are activated by absorption of visible light to initially form the excited singlet state, followed by transition to the long-lived excited triplet state. This triplet state can undergo photochemical reactions in the presence of oxygen to form reactive oxygen species (including singlet oxygen) that can destroy cancer cells, pathogenic microbes and unwanted tissue. The dual-specificity of PDT...
Source: Biochemical Journal - February 9, 2016 Category: Biochemistry Authors: Abrahamse, H., Hamblin, M. R. Tags: Disease, Biomolecules Review articles Source Type: research

Biophysical characterization of laforin-carbohydrate interaction
Laforin is a human dual-specificity phosphatase (DSP) involved in glycogen metabolism regulation containing a carbohydrate-binding module (CBM). Mutations in the gene coding for laforin are responsible for the development of Lafora disease, a progressive fatal myoclonus epilepsy with early onset, characterized by the intracellular deposition of abnormally branched, hyperphosphorylated insoluble glycogen-like polymers, called Lafora bodies. Despite the known importance of the CBM domain of laforin in the regulation of glycogen metabolism, the molecular mechanism of laforin–glycogen interaction is still poorly understo...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Dias, D. M., Furtado, J., Wasielewski, E., Cruz, R., Costello, B., Cole, L., Faria, T. Q., Baaske, P., Brito, R. M. M., Ciulli, A., Simoes, I., Macedo-Ribeiro, S., Faro, C., Geraldes, C. F. G. C., Castanheira, P. Tags: Disease, Biomolecules Research articles Source Type: research

The lipidome associated with the {gamma}-secretase complex is required for its integrity and activity
-Secretase is a multi-subunit membrane protease complex that catalyses the final intramembrane cleavage of the β-amyloid precursor protein (APP) during the neuronal production of amyloid-β peptides (Aβ), which are implicated as the causative agents of Alzheimer's disease (AD). In the present study, we report the reconstitution of a highly purified, active -secretase complex into proteoliposomes without exogenous lipids and provide the first direct evidence for the existence of a microenvironment of 53 molecular species from 11 major lipid classes specifically associated with the -secretase complex, incl...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Ayciriex, S., Gerber, H., Osuna, G. M. G., Chami, M., Stahlberg, H., Shevchenko, A., Fraering, P. C. Tags: Biomolecules, ChemBio Research articles Source Type: research

A novel phosphorylation site at Ser130 adjacent to the pseudosubstrate domain contributes to the activation of protein kinase C-{delta}
Protein kinase C- (PKC) is a signalling kinase that regulates many cellular responses. Although most studies focus on allosteric mechanisms that activate PKC at membranes, PKC also is controlled via multi-site phosphorylation [Gong et al. (2015) Mol. Cell. Biol. 35, 1727–1740]. The present study uses MS-based methods to identify PKC phosphorylation at Thr50 and Ser645 (in resting and PMA-treated cardiomyocytes) as well as Thr37, Thr38, Ser130, Thr164, Thr211, Thr215, Ser218, Thr295, Ser299 and Thr656 (as sites that increase with PMA). We focused on the consequences of phosphorylation at Ser130 and Thr141 (sites just ...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Gong, J., Holewinski, R. J., Van Eyk, J. E., Steinberg, S. F. Tags: Signalling Research articles Source Type: research

An integrated biochemical system for nitrate assimilation and nitric oxide detoxification in Bradyrhizobium japonicum
Rhizobia are recognized to establish N2-fixing symbiotic interactions with legume plants. Bradyrhizobium japonicum, the symbiont of soybeans, can denitrify and grow under free-living conditions with nitrate (NO3–) or nitrite (NO2–) as sole nitrogen source. Unlike related bacteria that assimilate NO3–, genes encoding the assimilatory NO3– reductase (nasC) and NO2– reductase (nirA) in B. japonicum are located at distinct chromosomal loci. The nasC gene is located with genes encoding an ABC-type NO3– transporter, a major facilitator family NO3–/NO2– transporter (NarK), flavoprot...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Cabrera, J. J., Salas, A., Torres, M. J., Bedmar, E. J., Richardson, D. J., Gates, A. J., Delgado, M. J. Tags: Energy, Metabolism Research articles Source Type: research

Conformational dynamics of Ca2+-dependent responses in the polycystin-2 C-terminal tail
PC2 (polycystin-2) forms a Ca2+-permeable channel in the cell membrane and its function is regulated by cytosolic Ca2+ levels. Mutations in the C-terminal tail of human PC2 (HPC2 Cterm) lead to autosomal dominant polycystic kidney disease. The HPC2 Cterm protein contains a Ca2+-binding site responsible for channel gating and function. To provide the foundation for understanding how Ca2+ regulates the channel through the HPC2 Cterm, we characterized Ca2+ binding and its conformational and dynamic responses within the HPC2 Cterm. By examining hydrogen–deuterium (H–D) exchange profiles, we show that part of the co...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Yang, Y., Hodsdon, M. E., Lolis, E. J., Ehrlich, B. E. Tags: Energy, Biomolecules Research articles Source Type: research

Crystal structure of the homocysteine methyltransferase MmuM from Escherichia coli
Homocysteine S-methyltransferases (HMTs, EC 2.1.1.0) catalyse the conversion of homocysteine to methionine using S-methylmethionine or S-adenosylmethionine as the methyl donor. HMTs play an important role in methionine biosynthesis and are widely distributed among micro-organisms, plants and animals. Additionally, HMTs play a role in metabolite repair of S-adenosylmethionine by removing an inactive diastereomer from the pool. The mmuM gene product from Escherichia coli is an archetypal HMT family protein and contains a predicted zinc-binding motif in the enzyme active site. In the present study, we demonstrate X-ray struct...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Li, K., Li, G., Bradbury, L. M. T., Hanson, A. D., Bruner, S. D. Tags: Biomolecules Research articles Source Type: research

PDLIM7 is a novel target of the ubiquitin ligase Nedd4-1 in skeletal muscle
Skeletal muscle atrophy remains a complication occurring both as a natural response to muscle disuse and as a pathophysiological response to illness such as diabetes mellitus and nerve injury, such as traumatic muscle denervation. The ubiquitin–proteasome system (UPS) is the predominant proteolytic machinery responsible for atrophy of skeletal muscle, and Nedd4-1 (neural precursor cell-expressed developmentally down-regulated 4-1) is one of a series of E3 ubiquitin ligases identified to mediate inactivity-induced muscle wasting. Targets of Nedd4-1 mediated ubiquitination in skeletal muscle remain poorly understood. I...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: D'Cruz, R., Plant, P. J., Pablo, L. A., Lin, S., Chackowicz, J., Correa, J., Bain, J., Batt, J. Tags: Cell, Signalling Research articles Source Type: research

PXR stimulates growth factor-mediated hepatocyte proliferation by cross-talk with the FOXO transcription factor
Growth factor-mediated hepatocyte proliferation is crucial in liver regeneration and the recovery of liver function after injury. The nuclear receptor, pregnane X receptor (PXR), is a key transcription factor for the xenobiotic-induced expression of genes associated with various liver functions. Recently, we reported that PXR activation stimulates xenobiotic-induced hepatocyte proliferation. In the present study, we investigated whether PXR activation also stimulates growth factor-mediated hepatocyte proliferation. In G0 phase-synchronized, immortalized mouse hepatocytes, serum or epidermal growth factor treatment increase...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Shizu, R., Abe, T., Benoki, S., Takahashi, M., Kodama, S., Miayata, M., Matsuzawa, A., Yoshinari, K. Tags: Metabolism, Signalling Research articles Source Type: research

miR-1343 attenuates pathways of fibrosis by targeting the TGF-{beta} receptors
Irreversible respiratory obstruction resulting from progressive airway damage, inflammation and fibrosis is a feature of several chronic respiratory diseases, including cystic fibrosis (CF), idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD). The cytokine transforming growth factor β (TGF-β) has a pivotal role in promoting lung fibrosis and is implicated in respiratory disease severity. In the present study, we show that a previously uncharacterized miRNA, miR-1343, reduces the expression of both TGF-β receptor 1 and 2 by directly targeting their 3'-UTRs. After TGF-&bet...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Stolzenburg, L. R., Wachtel, S., Dang, H., Harris, A. Tags: Cell, Disease Research articles Source Type: research

The role of N-glycans and the C-terminal loop of the subunit rBAT in the biogenesis of the cystinuria-associated transporter
The transport system b0,+ mediates reabsorption of dibasic amino acids and cystine in the kidney. It is made up of two disulfide-linked membrane subunits: the carrier, b0,+AT and the helper, rBAT (related to b0,+ amino acid transporter). rBAT mutations that impair biogenesis of the transporter cause type I cystinuria. It has been shown that upon assembly, b0,+AT prevents degradation and promotes folding of rBAT; then, rBAT traffics b0,+AT from the endoplasmic reticulum (ER) to the plasma membrane. The role of the N-glycans of rBAT and of its C-terminal loop, which has no homology to any other sequence, in biogenesis o...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Rius, M., Sala, L., Chillaron, J. Tags: Cell, Disease Research articles Source Type: research

The function of orthologues of the human Parkinson's disease gene LRRK2 across species: implications for disease modelling in preclinical research
In the period since LRRK2 (leucine-rich repeat kinase 2) was identified as a causal gene for late-onset autosomal dominant parkinsonism, a great deal of work has been aimed at understanding whether the LRRK2 protein might be a druggable target for Parkinson's disease (PD). As part of this effort, animal models have been developed to explore both the normal and the pathophysiological roles of LRRK2. However, LRRK2 is part of a wider family of proteins whose functions in different organisms remain poorly understood. In this review, we compare the information available on biochemical properties of LRRK2 homologues and ortholo...
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Langston, R. G., Rudenko, I. N., Cookson, M. R. Tags: Disease, Signalling Review articles Source Type: research

Sigma-1 receptors: a new pathway for the modulation of store-operated calcium entry
This study envisages a pathway through which cocaine modulates endothelial function via regulation of SOCE. The regulation of SOCE by sigma-1 receptors provides a novel and important pathway in Ca2+ signalling. (Source: Biochemical Journal)
Source: Biochemical Journal - January 25, 2016 Category: Biochemistry Authors: Rosado, J. A. Tags: Cell, Signalling Commentaries Source Type: research

Plasma-derived and synthetic high-density lipoprotein inhibit tissue factor in endothelial cells and monocytes
HDL (high-density lipoproteins) exert anti-thrombotic activities by preventing platelet adhesion and activation and by stimulating the protein C pathway and fibrinolysis. The aim of the present study was to assess the effect of plasma-derived and synthetic HDL on endothelial and monocyte expression of TF (tissue factor), the primary initiator of coagulation. HDL inhibited TF expression and activity in stimulated endothelial cells and monocytes in a dose-dependent way. Synthetic HDL fully retain the ability to inhibit TF expression in a dose-dependent manner; lipid-free apoA-I (apolipoprotein A-I) was not effective and neit...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Ossoli, A., Remaley, A. T., Vaisman, B., Calabresi, L., Gomaraschi, M. Tags: Metabolism, Cell Research articles Source Type: research

TRPC3 amplifies B-cell receptor-induced ERK signalling via protein kinase D-dependent Rap1 activation
Sustained activation of extracellular-signal-regulated kinase (ERK) has an important role in the decision regarding the cell fate of B-lymphocytes. Recently, we demonstrated that the diacylglycerol-activated non-selective cation channel canonical transient receptor potential 3 (TRPC3) is required for the sustained ERK activation induced by the B-cell receptor. However, the signalling mechanism underlying TRPC3-mediated ERK activation remains elusive. In the present study, we have shown that TRPC3 mediates Ca2+ influx to sustain activation of protein kinase D (PKD) in a protein kinase C-dependent manner in DT40 B-lymphocyte...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Numaga-Tomita, T., Nishida, M., Putney, J. W., Mori, Y. Tags: Cell, Signalling Research articles Source Type: research

Differential regulation by AMP and ADP of AMPK complexes containing different {gamma} subunit isoforms
The subunits of heterotrimeric AMPK complexes contain the binding sites for the regulatory adenine nucleotides AMP, ADP and ATP. We addressed whether complexes containing different isoforms display different responses to adenine nucleotides by generating cells stably expressing FLAG-tagged versions of the 1, 2 or 3 isoform. When assayed at a physiological ATP concentration (5 mM), 1- and 2-containing complexes were allosterically activated almost 10-fold by AMP, with EC50 values one to two orders of magnitude lower than the ATP concentration. By contrast, 3 complexes were barely activated by AMP under these conditions...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Ross, F. A., Jensen, T. E., Hardie, D. G. Tags: Energy, Signalling Research articles Source Type: research

Structural basis for the regulatory role of the PPxY motifs in the thioredoxin-interacting protein TXNIP
TXNIP (thioredoxin-interacting protein) negatively regulates the antioxidative activity of thioredoxin and participates in pleiotropic cellular processes. Its deregulation is linked to various human diseases, including diabetes, acute myeloid leukaemia and cardiovascular diseases. The E3 ubiquitin ligase Itch (Itchy homologue) polyubiquitinates TXNIP to promote its degradation via the ubiquitin–proteasome pathway, and this Itch-mediated polyubiquitination of TXNIP is dependent on the interaction of the four WW domains of Itch with the two PPxY motifs of TXNIP. However, the molecular mechanism of this interaction of T...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Liu, Y., Lau, J., Li, W., Tempel, W., Li, L., Dong, A., Narula, A., Qin, S., Min, J. Tags: ChemBio Research articles Source Type: research

BRICHOS binds to a designed amyloid-forming {beta}-protein and reduces proteasomal inhibition and aggresome formation
The BRICHOS domain is associated with proliferative, degenerative and amyloid diseases, and it has been shown to inhibit fibril formation and toxicity of the Alzheimer's disease-associated amyloid β-peptide. ProSP-C (prosurfactant protein C) BRICHOS binds to stretches of hydrophobic amino acid residues, which are unfolded or in β-strand conformation, suggesting that it may have broad anti-amyloid activity. We have studied the effect of the proSP-C BRICHOS domain on the designed amyloidogenic β-sheet proteins β17 and β23. β17 expressed in the secretory pathway of HEK (human embryonic kidney)-29...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Dolfe, L., Winblad, B., Johansson, J., Presto, J. Tags: Cell, Disease Research articles Source Type: research

Bacterial and plant HAD enzymes catalyse a missing phosphatase step in thiamin diphosphate biosynthesis
The penultimate step of thiamin diphosphate (ThDP) synthesis in plants and many bacteria is dephosphorylation of thiamin monophosphate (ThMP). Non-specific phosphatases have been thought to mediate this step and no genes encoding specific ThMP phosphatases (ThMPases) are known. Comparative genomic analysis uncovered bacterial haloacid dehalogenase (HAD) phosphatase family genes (from subfamilies IA and IB) that cluster on the chromosome with, or are fused to, thiamin synthesis genes and are thus candidates for the missing phosphatase (ThMPase). Three typical candidates (from Anaerotruncus colihominis, Dorea longicatena and...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Hasnain, G., Roje, S., Sa, N., Zallot, R., Ziemak, M. J., de Crecy-Lagard, V., Gregory, J. F., Hanson, A. D. Tags: Plant Research articles Source Type: research

Characterization of {alpha}-taxilin as a novel factor controlling the release of hepatitis C virus
Although it is well established that the release of HCV (hepatitis C virus) occurs through the secretory pathway, many aspects concerning the control of this process are not yet fully understood. α-Taxilin was identified as a novel binding partner of syntaxin-4 and of other members of the syntaxin family, which are part of SNARE (soluble N-ethylmaleimide-sensitive fusion protein-attachment protein receptor) complexes and so are involved in intracellular vesicle traffic. Since α-taxilin prevents t-SNARE (target SNARE) formation by binding exclusively to free syntaxin-4, it exerts an inhibitory effect on the vesi...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Elgner, F., Donnerhak, C., Ren, H., Medvedev, R., Schreiber, A., Weber, L., Heilmann, M., Ploen, D., Himmelsbach, K., Finkernagel, M., Klingel, K., Hildt, E. Tags: Cell, Disease Research articles Source Type: research

The intrinsically disordered tails of PTEN and PTEN-L have distinct roles in regulating substrate specificity and membrane activity
Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a lipid and protein phosphatase, and both activities are necessary for its role as a tumour suppressor. PTEN activity is controlled by phosphorylation of its intrinsically disordered C-terminal tail. A recently discovered variant of PTEN, PTEN-long (PTEN-L), has a 173-residue N-terminal extension that causes PTEN-L to exhibit unique behaviour, such as movement from one cell to another. Using hydrogen/deuterium exchange mass spectrometry (HDX–MS) and biophysical assays, we show that both the N-terminal extension of PTEN-L and C-terminal tail of PTEN a...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Masson, G. R., Perisic, O., Burke, J. E., Williams, R. L. Tags: Biomolecules, Signalling Research articles Source Type: research

Crystal structure of Mycobacterium tuberculosis O6-methylguanine-DNA methyltransferase protein clusters assembled on to damaged DNA
Mycobacterium tuberculosis O6-methylguanine-DNA methyltransferase (MtOGT) contributes to protect the bacterial GC-rich genome against the pro-mutagenic potential of O6-methylated guanine in DNA. Several strains of M. tuberculosis found worldwide encode a point-mutated O6-methylguanine-DNA methyltransferase (OGT) variant (MtOGT-R37L), which displays an arginine-to-leucine substitution at position 37 of the poorly functionally characterized N-terminal domain of the protein. Although the impact of this mutation on the MtOGT activity has not yet been proved in vivo, we previously demonstrated that a recombinant MtOGT-R37L...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Miggiano, R., Perugino, G., Ciaramella, M., Serpe, M., Rejman, D., Pav, O., Pohl, R., Garavaglia, S., Lahiri, S., Rizzi, M., Rossi, F. Tags: Biomolecules Research articles Source Type: research

TSPO: kaleidoscopic 18-kDa amid biochemical pharmacology, control and targeting of mitochondria
The 18-kDa translocator protein (TSPO) localizes in the outer mitochondrial membrane (OMM) of cells and is readily up-regulated under various pathological conditions such as cancer, inflammation, mechanical lesions and neurological diseases. Able to bind with high affinity synthetic and endogenous ligands, its core biochemical function resides in the translocation of cholesterol into the mitochondria influencing the subsequent steps of (neuro-)steroid synthesis and systemic endocrine regulation. Over the years, however, TSPO has also been linked to core cellular processes such as apoptosis and autophagy. It interacts and f...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Gatliff, J., Campanella, M. Tags: Review articles Source Type: research

ESCRT-III on endosomes: new functions, new activation pathway
The multivesicular body (MVB) pathway sorts ubiquitinated membrane cargo to intraluminal vesicles (ILVs) within the endosome, en route to the lysosomal lumen. The pathway involves the sequential action of conserved protein complexes [endosomal sorting complexes required for transport (ESCRTs)], culminating in the activation by ESCRT-II of ESCRT-III, a membrane-sculpting complex. Although this linear pathway of ESCRT activation is widely accepted, a study by Luzio and colleagues in a recent issue of the Biochemical Journal suggests that there is greater complexity in ESCRT-III activation, at least for some MVB cargoes. They...
Source: Biochemical Journal - January 5, 2016 Category: Biochemistry Authors: Woodman, P. Tags: Cell Commentaries Source Type: research

Smac mimetic with TNF-{alpha} targets Pim-1 isoforms and reactive oxygen species production to abrogate transformation from blebbishields
Cancer cells are capable of sphere formation (transformation) through reactive oxygen species (ROS) and glycolysis shift. Transformation is linked to tumorigenesis and therapy resistance, hence targeting regulators of ROS and glycolysis is important for cancer therapeutic candidates. Here, we demonstrate that Smac mimetic AZ58 in combination with tumour necrosis factor-α (TNF-α) was able to inhibit the production of ROS, inhibit glycolysis through Pim-1 kinase-mediated Ser-112 phosphorylation of BAD, and increase depolarization of mitochondria. We also identified mitochondrial isoforms of Pim-1 kinase that...
Source: Biochemical Journal - December 9, 2015 Category: Biochemistry Authors: Jinesh, G. G., Laing, N. M., Kamat, A. M. Tags: Metabolism, Cell Research articles Source Type: research

LL-37-induced host cell cytotoxicity depends on cellular expression of the globular C1q receptor (p33)
The human host-defence peptide (HDP) LL-37 not only displays anti-microbial activity but also immune-modulating properties that trigger intracellular signalling events in host cells. Since the cytolytic activity of high LL-37 concentrations affects cell viability, the function of LL-37 requires tight regulation. Eukaryotic cells therefore benefit from protective measures to prevent harmful effects of LL-37. p33, also known as globular C1q receptor (gC1qR), is reported to act as an LL-37 antagonist by binding the peptide, thereby reducing its cytotoxic activity. In the present report, we show that high levels of endogenous ...
Source: Biochemical Journal - December 9, 2015 Category: Biochemistry Authors: Svensson, D., Wilk, L., Morgelin, M., Herwald, H., Nilsson, B.-O. Tags: Cell Research articles Source Type: research

Glycosomal bromodomain factor 1 from Trypanosoma cruzi enhances trypomastigote cell infection and intracellular amastigote growth
Acetylation is a ubiquitous protein modification present in prokaryotic and eukaryotic cells that participates in the regulation of many cellular processes. The bromodomain is the only domain known to bind acetylated lysine residues. In the last few years, many bromodomain inhibitors have been developed in order to treat diseases caused by aberrant acetylation of lysine residues and have been tested as anti-parasitic drugs. In the present paper, we report the first characterization of Trypanosoma cruzi bromodomain factor 1 (TcBDF1). TcBDF1 is expressed in all life cycle stages, but it is developmentally regulated. It local...
Source: Biochemical Journal - December 9, 2015 Category: Biochemistry Authors: Ritagliati, C., Villanova, G. V., Alonso, V. L., Zuma, A. A., Cribb, P., Motta, M. C. M., Serra, E. C. Tags: Metabolism, Cell Research articles Source Type: research

Converting the bis-FeIV state of the diheme enzyme MauG to Compound I decreases the reorganization energy for electron transfer
The electron transfer (ET) properties of two types of high-valent hemes were studied within the same protein matrix; the bis-FeIV state of MauG and the Compound I state of Y294H MauG. The latter is formed as a consequence of mutation of the tyrosine which forms the distal axial ligand of the six-coordinate heme that allows it to stabilize FeIV in the absence of an external ligand. The rates of the ET reaction of each high-valent species with the type I copper protein, amicyanin, were determined at different temperatures and analysed by ET theory. The reaction with bis-FeIV wild-type (WT) MauG exhibited a reorgani...
Source: Biochemical Journal - December 9, 2015 Category: Biochemistry Authors: Dow, B. A., Davidson, V. L. Tags: Energy, Biomolecules Research articles Source Type: research

Structural and functional insight into the different oxidation states of SAV1875 from Staphylococcus aureus
The DJ-1/ThiJ/PfpI superfamily is a group of proteins found in diverse organisms. This superfamily includes versatile proteins, such as proteases, chaperones, heat-shock proteins and human Parkinson's disease protein. Most members of the DJ-1/ThiJ/PfpI superfamily are oligomers and are classified into subfamilies depending on discriminating quaternary structures (DJ-1, YhbO and Hsp types). SAV1875, a conserved protein from Staphylococcus aureus, is a member of the YhbO-type subfamily. However, its structure and function remain unknown. Thus, to understand the function and activity mechanism of this protein, the crystal str...
Source: Biochemical Journal - December 9, 2015 Category: Biochemistry Authors: Kim, H. J., Kwon, A.-R., Lee, B.-J. Tags: Biomolecules, ChemBio Research articles Source Type: research

Zinc-induced oligomerization of zinc {alpha}2 glycoprotein reveals multiple fatty acid-binding sites
Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigated. Analytical ultracentrifugation (AUC) and CD showed that zinc, but not other divalent metals, causes ZAG to oligo...
Source: Biochemical Journal - December 9, 2015 Category: Biochemistry Authors: Zahid, H., Miah, L., Lau, A. M., Brochard, L., Hati, D., Bui, T. T. T., Drake, A. F., Gor, J., Perkins, S. J., McDermott, L. C. Tags: Metabolism, Biomolecules Research articles Source Type: research

Metastasis-associated S100A4 is a specific amine donor and an activity-independent binding partner of transglutaminase-2
Transglutaminase-2 (TG2) is best known as a Ca2+-dependent cross-linking enzyme; however, some of its extracellular matrix-related functions are independent of its catalytic activity and include matrix remodelling, adhesion and migration. S100A4 belongs to the Ca2+-binding EF-hand S100 protein family and acts both intra- and extra-cellularly through binding to various partners. It regulates cell migration and its overexpression is strongly associated with metastasis and poor survival in various cancers. It has recently been suggested that TG2 mediates S100A4-dependent tumour cell migration. In the present study we provide ...
Source: Biochemical Journal - December 9, 2015 Category: Biochemistry Authors: Biri, B., Kiss, B., Kiraly, R., Schlosser, G., Lang, O., Kőhidai, L., Fesus, L., Nyitray, L. Tags: Disease, Biomolecules Research articles Source Type: research

Bisecting GlcNAc modification stabilizes BACE1 protein under oxidative stress conditions
β-Site amyloid precursor protein-cleaving enzyme-1 (BACE1) is a protease essential for amyloid-β (Aβ) production in Alzheimer's disease (AD). BACE1 protein is known to be up-regulated by oxidative stress-inducing stimuli but the mechanism for this up-regulation still needs to be clarified. We have recently found that BACE1 is modified with bisecting N-acetylglucosamine (GlcNAc) by N-acetylglucosaminyltransferase-III (GnT-III, encoded by the Mgat3 gene) and that GnT-III deficiency reduces Aβ-plaque formation in the brain by accelerating lysosomal degradation of BACE1. Therefore, we hypothesized that bise...
Source: Biochemical Journal - December 9, 2015 Category: Biochemistry Authors: Kizuka, Y., Nakano, M., Kitazume, S., Saito, T., Saido, T. C., Taniguchi, N. Tags: Disease, Biomolecules Research articles Source Type: research