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Multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis
The endoplasmic reticulum (ER)-Golgi sterol transfer activity of oxysterol-binding protein (OSBP) regulates sphingomyelin (SM) synthesis, as well as post-Golgi cholesterol efflux pathways. The phosphorylation and ER-Golgi localization of OSBP are correlated, suggesting this modification regulates th...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The American Society for Cell Biology
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3442410/ https://www.ncbi.nlm.nih.gov/pubmed/22875984 http://dx.doi.org/10.1091/mbc.E12-04-0283 |
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author | Goto, Asako Liu, Xinwei Robinson, Carolyn-Ann Ridgway, Neale D. |
author_facet | Goto, Asako Liu, Xinwei Robinson, Carolyn-Ann Ridgway, Neale D. |
author_sort | Goto, Asako |
collection | PubMed |
description | The endoplasmic reticulum (ER)-Golgi sterol transfer activity of oxysterol-binding protein (OSBP) regulates sphingomyelin (SM) synthesis, as well as post-Golgi cholesterol efflux pathways. The phosphorylation and ER-Golgi localization of OSBP are correlated, suggesting this modification regulates the directionality and/or specificity of transfer activity. In this paper, we report that phosphorylation on two serine-rich motifs, S381-S391 (site 1) and S192, S195, S200 (site 2), specifically controls OSBP activity at the ER. A phosphomimetic of the SM/cholesterol-sensitive phosphorylation site 1 (OSBP-S5E) had increased in vitro cholesterol and 25-hydroxycholesterol–binding capacity, and cholesterol extraction from liposomes, but reduced transfer activity. Phosphatidylinositol 4-phosphate (PI(4)P) and cholesterol competed for a common binding site on OSBP; however, direct binding of PI(4)P was not affected by site 1 phosphorylation. Individual site 1 and site 2 phosphomutants supported oxysterol activation of SM synthesis in OSBP-deficient CHO cells. However, a double site1/2 mutant (OSBP-S381A/S3D) was deficient in this activity and was constitutively colocalized with vesicle-associated membrane protein–associated protein A (VAP-A) in a collapsed ER network. This study identifies phosphorylation regulation of sterol and VAP-A binding by OSBP in the ER, and PI(4)P as an alternate ligand that could be exchanged for sterol in the Golgi apparatus. |
format | Online Article Text |
id | pubmed-3442410 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | The American Society for Cell Biology |
record_format | MEDLINE/PubMed |
spelling | pubmed-34424102012-11-30 Multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis Goto, Asako Liu, Xinwei Robinson, Carolyn-Ann Ridgway, Neale D. Mol Biol Cell Articles The endoplasmic reticulum (ER)-Golgi sterol transfer activity of oxysterol-binding protein (OSBP) regulates sphingomyelin (SM) synthesis, as well as post-Golgi cholesterol efflux pathways. The phosphorylation and ER-Golgi localization of OSBP are correlated, suggesting this modification regulates the directionality and/or specificity of transfer activity. In this paper, we report that phosphorylation on two serine-rich motifs, S381-S391 (site 1) and S192, S195, S200 (site 2), specifically controls OSBP activity at the ER. A phosphomimetic of the SM/cholesterol-sensitive phosphorylation site 1 (OSBP-S5E) had increased in vitro cholesterol and 25-hydroxycholesterol–binding capacity, and cholesterol extraction from liposomes, but reduced transfer activity. Phosphatidylinositol 4-phosphate (PI(4)P) and cholesterol competed for a common binding site on OSBP; however, direct binding of PI(4)P was not affected by site 1 phosphorylation. Individual site 1 and site 2 phosphomutants supported oxysterol activation of SM synthesis in OSBP-deficient CHO cells. However, a double site1/2 mutant (OSBP-S381A/S3D) was deficient in this activity and was constitutively colocalized with vesicle-associated membrane protein–associated protein A (VAP-A) in a collapsed ER network. This study identifies phosphorylation regulation of sterol and VAP-A binding by OSBP in the ER, and PI(4)P as an alternate ligand that could be exchanged for sterol in the Golgi apparatus. The American Society for Cell Biology 2012-09-15 /pmc/articles/PMC3442410/ /pubmed/22875984 http://dx.doi.org/10.1091/mbc.E12-04-0283 Text en © 2012 Goto et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). “ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society of Cell BD; are registered trademarks of The American Society of Cell Biology. |
spellingShingle | Articles Goto, Asako Liu, Xinwei Robinson, Carolyn-Ann Ridgway, Neale D. Multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis |
title | Multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis |
title_full | Multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis |
title_fullStr | Multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis |
title_full_unstemmed | Multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis |
title_short | Multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis |
title_sort | multisite phosphorylation of oxysterol-binding protein regulates sterol binding and activation of sphingomyelin synthesis |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3442410/ https://www.ncbi.nlm.nih.gov/pubmed/22875984 http://dx.doi.org/10.1091/mbc.E12-04-0283 |
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