A conserved, lipid-mediated sorting mechanism of yeast Ist2 and mammalian STIM proteins to the peripheral ER.
Traffic
; 10(12): 1802-18, 2009 Dec.
Article
em En
| MEDLINE
| ID: mdl-19845919
ABSTRACT
Sorting of yeast Ist2 to the plasma membrane (PM) or the cortical endoplasmic reticulum (ER) requires a cortical sorting signal (CSS(Ist2)) that interacts with lipids including phosphatidylinositol-4,5-bisphosphate (PI(4,5)P(2)) at the PM. Here, we show that the expression of Ist2 in mammalian cells resulted in a peripheral patch-like localization without any detection of Ist2 at the cell surface. Attached to C-termini of mammalian integral membrane proteins, the CSS(Ist2) targeted these proteins to PM-associated domains of the ER and abolished trafficking via the classical secretory pathway. The interaction of integral membrane proteins with PI(4,5)P(2) at the PM created ER-PM contacts. This process is similar to the regulated coupling of ER domains to the PM via stromal interaction molecule (STIM) proteins during store-operated Ca(2+) entry (SOCE). The CSS(Ist2) and the C-terminus of the ER-located Ca(2+) sensor STIM2 were sufficient to bind PI(4,5)P(2) and PI(3,4,5)P(3) at the PM, showing that an evolutionarily conserved mechanism is involved in the sorting of integral membrane proteins to PM-associated domains of the ER. Yeast Ist2 and STIM2 share a common basic and amphipathic signal at their extreme C-termini. STIM1 showed binding preference for liposomes containing PI(4,5)P(2), suggesting a specific contribution of lipids to the recruitment of ER domains to the PM during SOCE.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Transporte Proteico
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Proteínas de Saccharomyces cerevisiae
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Retículo Endoplasmático
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Lipídeos
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Proteínas de Membrana
Limite:
Animals
Idioma:
En
Revista:
Traffic
Ano de publicação:
2009
Tipo de documento:
Article