The counterflow transport of sterols and PI4P.
Biochim Biophys Acta
; 1861(8 Pt B): 940-951, 2016 Aug.
Article
em En
| MEDLINE
| ID: mdl-26928592
ABSTRACT
Cholesterol levels in intracellular membranes are constantly adjusted to match with specific organelle functions. Cholesterol is kept high in the plasma membrane (PM) because it is essential for its barrier function, while low levels are found in the endoplasmic reticulum (ER) where cholesterol mediates feedback control of its own synthesis by sterol-sensor proteins. The ERâGolgiâPM concentration gradient of cholesterol in mammalian cells, and ergosterol in yeast, appears to be sustained by specific intracellular transport processes, which are mostly mediated by lipid transfer proteins (LTPs). Here we review a recently described function of two LTPs, OSBP and its yeast homolog Osh4p, which consists in creating a sterol gradient between membranes by vectorial transport. OSBP also contributes to the formation of ER/Golgi membrane contact sites, which are important hubs for the transfer of several lipid species. OSBP and Osh4p organize a counterflow transport of lipids whereby sterols are exchanged for the phosphoinositide PI4P, which is used as a fuel to drive sterol transport. This article is part of a Special Issue entitled The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Transporte
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Receptores de Esteroides
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Colesterol
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Fosfatos de Fosfatidilinositol
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Proteínas de Saccharomyces cerevisiae
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Proteínas de Membrana
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article