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Rapid inactivation of the yeast Sec complex selectively blocks transport of post-translationally translocated proteins
The yeast endoplasmic reticulum has three distinct protein translocation channels. The heterotrimeric Sec61 and Ssh1 complexes, which bind translating ribosomes, mediate cotranslational translocation of proteins targeted to the endoplasmic reticulum by the signal recognition particle (SRP) and SRP r...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Society for Biochemistry and Molecular Biology
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8503631/ https://www.ncbi.nlm.nih.gov/pubmed/34492269 http://dx.doi.org/10.1016/j.jbc.2021.101171 |
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author | Yi, Jae Kyo Fujita, Hidenobu Mandon, Elisabet C. Gilmore, Reid |
author_facet | Yi, Jae Kyo Fujita, Hidenobu Mandon, Elisabet C. Gilmore, Reid |
author_sort | Yi, Jae Kyo |
collection | PubMed |
description | The yeast endoplasmic reticulum has three distinct protein translocation channels. The heterotrimeric Sec61 and Ssh1 complexes, which bind translating ribosomes, mediate cotranslational translocation of proteins targeted to the endoplasmic reticulum by the signal recognition particle (SRP) and SRP receptor targeting pathway, whereas the heptameric Sec complex has been proposed to mediate ribosome-independent post-translational translocation of proteins with less hydrophobic signal sequences that escape recognition by the SRP. However, multiple reports have proposed that the Sec complex may function cotranslationally and be involved in translocation or integration of SRP-dependent protein translocation substrates. To provide insight into these conflicting views, we induced expression of the tobacco etch virus protease to achieve rapid inactivation of the Sec complex by protease-mediated cleavage within the cytoplasmic domain of the Sec63 protein. Protein translocation assays conducted after tobacco etch virus protease induction revealed a complete block in translocation of two well-characterized substrates of the Sec complex, carboxypeptidase Y (CPY) and Gas1p, when the protease cleavage sites were located at structural domain boundaries in Sec63. However, integration of SRP-dependent membrane protein substrates was not detectably impacted. Moreover, redirecting CPY to the cotranslational pathway by increasing the hydrophobicity of the signal sequence rendered translocation of CPY insensitive to inactivation of the Sec complex. We conclude that the Sec complex is primarily responsible for the translocation of yeast secretome proteins with marginally hydrophobic signal sequences. |
format | Online Article Text |
id | pubmed-8503631 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | American Society for Biochemistry and Molecular Biology |
record_format | MEDLINE/PubMed |
spelling | pubmed-85036312021-10-18 Rapid inactivation of the yeast Sec complex selectively blocks transport of post-translationally translocated proteins Yi, Jae Kyo Fujita, Hidenobu Mandon, Elisabet C. Gilmore, Reid J Biol Chem Research Article The yeast endoplasmic reticulum has three distinct protein translocation channels. The heterotrimeric Sec61 and Ssh1 complexes, which bind translating ribosomes, mediate cotranslational translocation of proteins targeted to the endoplasmic reticulum by the signal recognition particle (SRP) and SRP receptor targeting pathway, whereas the heptameric Sec complex has been proposed to mediate ribosome-independent post-translational translocation of proteins with less hydrophobic signal sequences that escape recognition by the SRP. However, multiple reports have proposed that the Sec complex may function cotranslationally and be involved in translocation or integration of SRP-dependent protein translocation substrates. To provide insight into these conflicting views, we induced expression of the tobacco etch virus protease to achieve rapid inactivation of the Sec complex by protease-mediated cleavage within the cytoplasmic domain of the Sec63 protein. Protein translocation assays conducted after tobacco etch virus protease induction revealed a complete block in translocation of two well-characterized substrates of the Sec complex, carboxypeptidase Y (CPY) and Gas1p, when the protease cleavage sites were located at structural domain boundaries in Sec63. However, integration of SRP-dependent membrane protein substrates was not detectably impacted. Moreover, redirecting CPY to the cotranslational pathway by increasing the hydrophobicity of the signal sequence rendered translocation of CPY insensitive to inactivation of the Sec complex. We conclude that the Sec complex is primarily responsible for the translocation of yeast secretome proteins with marginally hydrophobic signal sequences. American Society for Biochemistry and Molecular Biology 2021-09-04 /pmc/articles/PMC8503631/ /pubmed/34492269 http://dx.doi.org/10.1016/j.jbc.2021.101171 Text en © 2021 The Authors https://creativecommons.org/licenses/by/4.0/This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Research Article Yi, Jae Kyo Fujita, Hidenobu Mandon, Elisabet C. Gilmore, Reid Rapid inactivation of the yeast Sec complex selectively blocks transport of post-translationally translocated proteins |
title | Rapid inactivation of the yeast Sec complex selectively blocks transport of post-translationally translocated proteins |
title_full | Rapid inactivation of the yeast Sec complex selectively blocks transport of post-translationally translocated proteins |
title_fullStr | Rapid inactivation of the yeast Sec complex selectively blocks transport of post-translationally translocated proteins |
title_full_unstemmed | Rapid inactivation of the yeast Sec complex selectively blocks transport of post-translationally translocated proteins |
title_short | Rapid inactivation of the yeast Sec complex selectively blocks transport of post-translationally translocated proteins |
title_sort | rapid inactivation of the yeast sec complex selectively blocks transport of post-translationally translocated proteins |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8503631/ https://www.ncbi.nlm.nih.gov/pubmed/34492269 http://dx.doi.org/10.1016/j.jbc.2021.101171 |
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