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Traffic

Title:		"An ER membrane protein, Sop4, facilitates ER export of the yeast plasma membrane [H+]ATPase, Pma1"
Author(s):		Luo WJ; Gong XH; Chang A;
Address:		"Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, New York 10461, USA"
Journal Title:		Traffic
Year:		2002
Volume:		3
Issue:		10
Page Number:		730 - 739
DOI:		10.1034/j.1600-0854.2002.31005.x
ISSN/ISBN:		1398-9219 (Print) 1398-9219 (Linking)
Abstract:		"We have analyzed the mechanism by which Sop4, a novel ER membrane protein, regulates quality control and intracellular transport of Pma1-7, a mutant plasma membrane ATPase. At the restrictive temperature, newly synthesized Pma1-7 is targeted for vacuolar degradation instead of being correctly delivered to the cell surface. Loss of Sop4 at least partially corrects vacuolar mislocalization, allowing Pma1-7 routing to the plasma membrane. Ste2-3 is a mutant pheromone receptor which, like Pma1-7, is defective in targeting to the cell surface, resulting in a mating defect. sop4delta suppresses the mating defect of ste2-3 cells as well as the growth defect of pma1-7. Visualization of newly synthesized Pma1-7 in sop4delta cells by indirect immunofluorescence reveals delayed export from the ER. Similarly, ER export of wild-type Pma1 is delayed in the absence of Sop4 although intracellular transport of Gas1 and CPY is unaffected. These observations suggest a model in which a selective increase in ER residence time for Pma1-7 may allow it to achieve a more favorable conformation for subsequent delivery to the plasma membrane. In support of this model, newly synthesized Pma1-7 is also routed to the plasma membrane upon release from a general block of ER-to-Golgi transport in sec13-1 cells"
Keywords:		"Base Sequence DNA Primers Endoplasmic Reticulum/*metabolism Fungal Proteins/genetics/*metabolism Genes, Suppressor Protein Transport Proton-Translocating ATPases/*metabolism Saccharomyces cerevisiae Proteins/*metabolism;"
Notes:		"MedlineLuo, Wen-jie Gong, Xiao-hua Chang, Amy eng GM58212/GM/NIGMS NIH HHS/ Research Support, U.S. Gov't, P.H.S. England 2002/09/17 Traffic. 2002 Oct; 3(10):730-9. doi: 10.1034/j.1600-0854.2002.31005.x"