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Yeast GGA proteins interact with GTP‐bound Arf and facilitate transport through the Golgi
Author(s) -
Zhdankina Olga,
Strand Nicole L.,
Redmond John M.,
Boman Annette L.
Publication year - 2001
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/1097-0061(200101)18:1<1::aid-yea644>3.0.co;2-5
Subject(s) - biology , golgi apparatus , endocytic cycle , yeast , adp ribosylation factor , microbiology and biotechnology , endocytosis , effector , transport protein , biochemistry , amino acid , saccharomyces cerevisiae , receptor , endoplasmic reticulum
ARF proteins regulate the formation of transport vesicles at many steps of the secretory and endocytic pathways. A recently identified family of ARF effectors, named GGAs, appears to regulate membrane traffic exiting the trans ‐Golgi network in mammalian cells (Boman et al ., 2000). We have identified two GGA homologues in the yeast S. cerevisiae . These previously uncharacterized open reading frames, YDR358w and YHR108w, have been named GGA1 and GGA2 , respectively. Using the two‐hybrid assay and GST‐affinity chromatography, we show that Gga1p and Gga2p interact with Arf1p and Arf2p in a GTP‐dependent manner, suggesting that both are functional homologues of the human GGA proteins. The Arf‐binding domain resides in the amino‐terminal half of Gga1p (amino acids 170–330), and the carboxy‐terminal 100 amino acids resemble the γ‐adaptin ‘ear domain’. Gene deletion experiments indicate that GGA1 and GGA2 are not essential genes, as single and double knockouts are viable at both 30°C and 37°C. However, cells lacking GGA1 and GGA2 exhibit defects in invertase processing and CPY sorting, but not endocytosis. We conclude that yeast Gga proteins are effectors of Arf in yeast that facilitate traffic through the late Golgi. Copyright © 2000 John Wiley & Sons, Ltd.