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Kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of Candida albicans into a soluble cytosolic form
Cytosolic α-mannosidases are glycosyl hydrolases that participate in the catabolism of cytosolic free N-oligosaccharides. Two soluble α-mannosidases (E-I and E-II) belonging to glycosyl hydrolases family 47 have been described in Candida albicans. We demonstrate that addition of pepstatin A during t...
Autores principales: | , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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Microbiology Society
2008
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885623/ https://www.ncbi.nlm.nih.gov/pubmed/19047746 http://dx.doi.org/10.1099/mic.0.2008/019315-0 |
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author | Mora-Montes, Héctor M. Bader, Oliver López-Romero, Everardo Zinker, Samuel Ponce-Noyola, Patricia Hube, Bernhard Gow, Neil A. R. Flores-Carreón, Arturo |
author_facet | Mora-Montes, Héctor M. Bader, Oliver López-Romero, Everardo Zinker, Samuel Ponce-Noyola, Patricia Hube, Bernhard Gow, Neil A. R. Flores-Carreón, Arturo |
author_sort | Mora-Montes, Héctor M. |
collection | PubMed |
description | Cytosolic α-mannosidases are glycosyl hydrolases that participate in the catabolism of cytosolic free N-oligosaccharides. Two soluble α-mannosidases (E-I and E-II) belonging to glycosyl hydrolases family 47 have been described in Candida albicans. We demonstrate that addition of pepstatin A during the preparation of cell homogenates enriched α-mannosidase E-I at the expense of E-II, indicating that the latter is generated by proteolysis during cell disruption. E-I corresponded to a polypeptide of 52 kDa that was associated with mannosidase activity and was recognized by an anti-α1,2-mannosidase antibody. The N-mannan core trimming properties of the purified enzyme E-I were consistent with its classification as a family 47 α1,2-mannosidase. Differential density-gradient centrifugation of homogenates revealed that α1,2-mannosidase E-I was localized to the cytosolic fraction and Golgi-derived vesicles, and that a 65 kDa membrane-bound α1,2-mannosidase was present in endoplasmic reticulum and Golgi-derived vesicles. Distribution of α-mannosidase activity in a kex2Δ null mutant or in wild-type protoplasts treated with monensin demonstrated that the membrane-bound α1,2-mannosidase is processed by Kex2 protease into E-I, recognizing an atypical cleavage site of the precursor. Analysis of cytosolic free N-oligosaccharides revealed that cytosolic α1,2-mannosidase E-I trims free Man(8)GlcNAc(2) isomer B into Man(7)GlcNAc(2) isomer B. This is believed to be the first report demonstrating the presence of soluble α1,2-mannosidase from the glycosyl hydrolases family 47 in a cytosolic compartment of the cell. |
format | Text |
id | pubmed-2885623 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2008 |
publisher | Microbiology Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-28856232010-07-06 Kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of Candida albicans into a soluble cytosolic form Mora-Montes, Héctor M. Bader, Oliver López-Romero, Everardo Zinker, Samuel Ponce-Noyola, Patricia Hube, Bernhard Gow, Neil A. R. Flores-Carreón, Arturo Microbiology (Reading) Biochemistry and Molecular Biology Cytosolic α-mannosidases are glycosyl hydrolases that participate in the catabolism of cytosolic free N-oligosaccharides. Two soluble α-mannosidases (E-I and E-II) belonging to glycosyl hydrolases family 47 have been described in Candida albicans. We demonstrate that addition of pepstatin A during the preparation of cell homogenates enriched α-mannosidase E-I at the expense of E-II, indicating that the latter is generated by proteolysis during cell disruption. E-I corresponded to a polypeptide of 52 kDa that was associated with mannosidase activity and was recognized by an anti-α1,2-mannosidase antibody. The N-mannan core trimming properties of the purified enzyme E-I were consistent with its classification as a family 47 α1,2-mannosidase. Differential density-gradient centrifugation of homogenates revealed that α1,2-mannosidase E-I was localized to the cytosolic fraction and Golgi-derived vesicles, and that a 65 kDa membrane-bound α1,2-mannosidase was present in endoplasmic reticulum and Golgi-derived vesicles. Distribution of α-mannosidase activity in a kex2Δ null mutant or in wild-type protoplasts treated with monensin demonstrated that the membrane-bound α1,2-mannosidase is processed by Kex2 protease into E-I, recognizing an atypical cleavage site of the precursor. Analysis of cytosolic free N-oligosaccharides revealed that cytosolic α1,2-mannosidase E-I trims free Man(8)GlcNAc(2) isomer B into Man(7)GlcNAc(2) isomer B. This is believed to be the first report demonstrating the presence of soluble α1,2-mannosidase from the glycosyl hydrolases family 47 in a cytosolic compartment of the cell. Microbiology Society 2008-12 /pmc/articles/PMC2885623/ /pubmed/19047746 http://dx.doi.org/10.1099/mic.0.2008/019315-0 Text en Copyright © 2008, SGM http://creativecommons.org/licenses/by/2.5/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Biochemistry and Molecular Biology Mora-Montes, Héctor M. Bader, Oliver López-Romero, Everardo Zinker, Samuel Ponce-Noyola, Patricia Hube, Bernhard Gow, Neil A. R. Flores-Carreón, Arturo Kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of Candida albicans into a soluble cytosolic form |
title | Kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of Candida albicans into a soluble cytosolic form |
title_full | Kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of Candida albicans into a soluble cytosolic form |
title_fullStr | Kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of Candida albicans into a soluble cytosolic form |
title_full_unstemmed | Kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of Candida albicans into a soluble cytosolic form |
title_short | Kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of Candida albicans into a soluble cytosolic form |
title_sort | kex2 protease converts the endoplasmic reticulum α1,2-mannosidase of candida albicans into a soluble cytosolic form |
topic | Biochemistry and Molecular Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885623/ https://www.ncbi.nlm.nih.gov/pubmed/19047746 http://dx.doi.org/10.1099/mic.0.2008/019315-0 |
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