Subcellular Compartmentalization and Trafficking of the Biosynthetic Machinery for Fungal Melanin

Publication date: Available online 10 March 2016 Source:Cell Reports Author(s): Srijana Upadhyay, Xinping Xu, David Lowry, Jennifer C. Jackson, Robert W. Roberson, Xiaorong Lin Protection by melanin depends on its subcellular location. Although most filamentous fungi synthesize melanin via a polyketide synthase pathway, where and how melanin biosynthesis occurs and how it is deposited as extracellular granules remain elusive. Using a forward genetic screen in the pathogen Aspergillus fumigatus, we find that mutations in an endosomal sorting nexin abolish melanin cell-wall deposition. We find that all enzymes involved in the early steps of melanin biosynthesis are recruited to endosomes through a non-conventional secretory pathway. In contrast, late melanin enzymes accumulate in the cell wall. Such subcellular compartmentalization of the melanin biosynthetic machinery occurs in both A. fumigatus and A. nidulans. Thus, fungal melanin biosynthesis appears to be initiated in endosomes with exocytosis leading to melanin extracellular deposition, much like the synthesis and trafficking of mammalian melanin in endosomally derived melanosomes. Graphical abstract Teaser Upadhyay et al. discovered that fungal melanin biosynthetic machinery is recruited to endosomes, although it is composed of largely atypical secretory proteins. Compartmentalization and trafficking through the endosomal system might be important cellular principles governing fungal...
Source: Cell Reports - Category: Cytology Source Type: research

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Publication date: Available online 14 September 2019Source: Biocatalysis and Agricultural BiotechnologyAuthor(s): Urooj Javed, Asma Ansari, Afsheen Aman, Shah Ali Ul QaderAbstractIndustrial enzymes particularly xylanase have more demand due to its vast commercial application in paper and pulp, food, animal feed industries as well as for bioconversion of lignocellulosic waste into valuable chemical products. Xylanases are hydrolase enzyme that catalyzes the β-1,4 linkages in heteropolysaccharide xylan which ultimately yields xylose monomers Microbes mainly fungi are used to synthesize xylanase to catalyze xylan into it...
Source: Biocatalysis and Agricultural Biotechnology - Category: Biotechnology Source Type: research
AbstractsThe research explores the facile synthesis of some new phenylsulfamoyl carboxylic acids, their molecular docking, antimicrobial, and antioxidant activities. The procedure involved the mild reaction of amino acids with benzenesulfonyl chloride in a medium of aqueous base. The compounds were characterized using FTIR,1H-NMR,13C-NMR, and an elemental analysis. They were tested for their antimicrobial activities against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Candida albicans, and Aspergillus niger microorganisms. The antioxidant activity of the compounds we...
Source: Medicinal Chemistry Research - Category: Chemistry Source Type: research
Publication date: Available online 12 September 2019Source: Journal de Mycologie MédicaleAuthor(s): Dhoha Ghorbel, Inès Hadrich, Sourour Neji, Houaida Trabelsi, Hatem Belaaj, Hayet Sellami, Fatma Cheikhrouhou, Fattouma Makni, Ali AyadiAbstractAspergillus flavus is the second leading cause of invasive and non-invasive aspergillosis. Secretion of hydrolytic enzymes is considered as a virulence factor in this species. Our work aimed to study in vitro production of some virulence factors, to evaluate the biofilm production against human and avian A. flavus isolates and to investigate the antifungal susceptibility...
Source: Journal of Medical Mycology - Category: Biology Source Type: research
Publication date: December 2019Source: Phytochemistry Letters, Volume 34Author(s): Qi Song, Xiao-Ming Li, Xue-Yi Hu, Xin Li, Lu-Ping Chi, Hong-Lei Li, Bin-Gui WangAbstractSix secondary metabolites including a new aminobenzoic peptide seco-clavatustide B (1) and a new clavatoic acid derivative 5-acetyl-2,4-dihydroxy-3-methylbenzoic acid (3), were characterized from the EtOAc extracts of the Ascidian-derived endophytic fungus Aspergillus clavatus AS-107. The absolute configuration of compound 1 was established by electronic circular dichroism quantum calculation and the structure of compound 3 was elucidated on the basis of ...
Source: Phytochemistry Letters - Category: Chemistry Source Type: research
Updated Date: Fri, 13 Sep 2019 00:00:00 EDT
Source: DailyMed Drug Label Updates - Category: Drugs & Pharmacology Source Type: alerts
Aspergillus fumigatus is an opportunistic fungal pathogen that causes both chronic and acute invasive infections. Galactosaminogalactan (GAG) is an integral component of the A. fumigatus biofilm matrix and a key virulence factor. GAG is a heterogeneous linear α-1,4–linked exopolysaccharide of galactose and GalNAc that is partially deacetylated after secretion. A cluster of five co-expressed genes has been linked to GAG biosynthesis and modification. One gene in this cluster, ega3, is annotated as encoding a putative α-1,4-galactosaminidase belonging to glycoside hydrolase family 114 (GH114). Herein, we sh...
Source: Journal of Biological Chemistry - Category: Chemistry Authors: Tags: Editors ' Picks Source Type: research
Inhaled glucocorticoids form the mainstay of asthma treatment because of their anti-inflammatory effects in the lung. Exposure to the air pollutant ozone (O3) exacerbates chronic airways disease. We and others showed that presence of the epithelial-derived surfactant protein-D (SP-D) is important in immunoprotection against inflammatory changes including those induced by O3 inhalation in the airways. SP-D synthesis requires glucocorticoids. We hypothesized here that O3 exposure impairs glucocorticoid responsiveness (including SP-D production) in allergic airway inflammation. The effects of O3 inhalation and glucocorticoid ...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
Filamentous fungi generally form aggregated hyphal pellets in liquid culture. We previously reported that α-1,3-glucan-deficient mutants of Aspergillus nidulans did not form hyphal pellets and their hyphae were fully dispersed, and we suggested that α-1,3-glucan functions in hyphal aggregation. However, Aspergillus oryzae α-1,3-glucan-deficient (AGΔ) mutants still form small pellets; therefore, we hypothesized that another factor responsible for forming hyphal pellets remains in these mutants. Here, we identified an extracellular matrix polysaccharide galactosaminogalactan (GAG) as such a factor. To...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
utarowska Studies on the functionalization of materials used for the construction of filtering facepiece respirators (FFRs) relate to endowing fibers with biocidal properties. There is also a real need for reducing moisture content accumulating in such materials during FFR use, as it would lead to decreased microorganism survival. Thus, in our study, we propose the use of superabsorbent polymers (SAPs), together with a biocidal agent (biohalloysite), as additives in the manufacturing of polypropylene/polyester (PP/PET) multifunctional filtering material (MFM). The aim of this study was to evaluate the MFM for stability...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research
In this report, overexpression of codon-optimized gene Au8003 resulted in a detectable production of oph F in E. coli. In subsequent modulation of culture conditions, pentose arabinose allowed a more than 10-fold improvement of production than that of glycerol. To achieve a higher titer, the whole mevalonate pathway and an additional copy of isopentenyl diphosphate isomerase gene were assembled, leading to approximately 24-fold and 60-fold yield increases, respectively. The above four terpene synthase genes related to ophiobolin production in strain 094102 were individually or combinatorially overexpressed with Au8003 to m...
Source: Applied Microbiology and Biotechnology - Category: Microbiology Authors: Tags: Appl Microbiol Biotechnol Source Type: research
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