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Stable Signal Peptides and the Response to Secretion Stress in Staphylococcus aureus
Protein secretion is essential, but how it is managed is poorly understood. In bacteria, most secreted proteins require release from the outer surface of the cytoplasmic membrane by type I signal peptidase (SPase), which cleaves the mature protein from its membrane-bound N-terminal signal peptide. A...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Society for Microbiology
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5727409/ https://www.ncbi.nlm.nih.gov/pubmed/29233892 http://dx.doi.org/10.1128/mBio.01507-17 |
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author | Craney, Arryn Romesberg, Floyd E. |
author_facet | Craney, Arryn Romesberg, Floyd E. |
author_sort | Craney, Arryn |
collection | PubMed |
description | Protein secretion is essential, but how it is managed is poorly understood. In bacteria, most secreted proteins require release from the outer surface of the cytoplasmic membrane by type I signal peptidase (SPase), which cleaves the mature protein from its membrane-bound N-terminal signal peptide. As the first step that occurs outside the protected cytoplasmic environment and because insufficient activity can rapidly result in the toxic accumulation of preproteins, the activity of SPase is expected to be closely monitored and perhaps supplemented when insufficient. Indeed, we previously demonstrated that inhibition of SPase in Staphylococcus aureus results in derepression of the ayrRABC operon, which encodes an alternate mechanism to release proteins. However, in this case, the proteins are released with partially intact signal peptides, with the exception of IsaA, which is released with a virtually intact signal peptide. Here we show that mutation of AyrA [ayrA(R233K)] results in constitutive derepression of ayrRABC and that mutation of IsaA’s signal peptide [isaA(K2Q)] results in hyperderepression upon SPase inhibition, which also requires AyrA. Further studies demonstrate that the inducing signal for ayrRABC derepression is accumulation of a subset of preproteins with signal peptides that are stable toward further processing and that the signal is critically amplified by the K2Q mutation and relayed to AyrR by AyrA. These results elucidate the mechanism by which S. aureus monitors and responds to secretion stress. The presence of ayrRA in other bacteria suggests that it may represent a general strategy linking membrane stress to appropriate transcriptional responses. |
format | Online Article Text |
id | pubmed-5727409 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | American Society for Microbiology |
record_format | MEDLINE/PubMed |
spelling | pubmed-57274092017-12-14 Stable Signal Peptides and the Response to Secretion Stress in Staphylococcus aureus Craney, Arryn Romesberg, Floyd E. mBio Observation Protein secretion is essential, but how it is managed is poorly understood. In bacteria, most secreted proteins require release from the outer surface of the cytoplasmic membrane by type I signal peptidase (SPase), which cleaves the mature protein from its membrane-bound N-terminal signal peptide. As the first step that occurs outside the protected cytoplasmic environment and because insufficient activity can rapidly result in the toxic accumulation of preproteins, the activity of SPase is expected to be closely monitored and perhaps supplemented when insufficient. Indeed, we previously demonstrated that inhibition of SPase in Staphylococcus aureus results in derepression of the ayrRABC operon, which encodes an alternate mechanism to release proteins. However, in this case, the proteins are released with partially intact signal peptides, with the exception of IsaA, which is released with a virtually intact signal peptide. Here we show that mutation of AyrA [ayrA(R233K)] results in constitutive derepression of ayrRABC and that mutation of IsaA’s signal peptide [isaA(K2Q)] results in hyperderepression upon SPase inhibition, which also requires AyrA. Further studies demonstrate that the inducing signal for ayrRABC derepression is accumulation of a subset of preproteins with signal peptides that are stable toward further processing and that the signal is critically amplified by the K2Q mutation and relayed to AyrR by AyrA. These results elucidate the mechanism by which S. aureus monitors and responds to secretion stress. The presence of ayrRA in other bacteria suggests that it may represent a general strategy linking membrane stress to appropriate transcriptional responses. American Society for Microbiology 2017-12-12 /pmc/articles/PMC5727409/ /pubmed/29233892 http://dx.doi.org/10.1128/mBio.01507-17 Text en Copyright © 2017 Craney and Romesberg. https://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Observation Craney, Arryn Romesberg, Floyd E. Stable Signal Peptides and the Response to Secretion Stress in Staphylococcus aureus |
title | Stable Signal Peptides and the Response to Secretion Stress in Staphylococcus aureus |
title_full | Stable Signal Peptides and the Response to Secretion Stress in Staphylococcus aureus |
title_fullStr | Stable Signal Peptides and the Response to Secretion Stress in Staphylococcus aureus |
title_full_unstemmed | Stable Signal Peptides and the Response to Secretion Stress in Staphylococcus aureus |
title_short | Stable Signal Peptides and the Response to Secretion Stress in Staphylococcus aureus |
title_sort | stable signal peptides and the response to secretion stress in staphylococcus aureus |
topic | Observation |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5727409/ https://www.ncbi.nlm.nih.gov/pubmed/29233892 http://dx.doi.org/10.1128/mBio.01507-17 |
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