Abstract
The Gga proteins represent a family of ubiquitously expressed clathrin adaptors engaged in vesicle budding at the tubular endosomal network/trans Golgi network. Their membrane recruitment is commonly thought to involve interactions with Arf and signals in cargo through the so-called VHS domain. For yeast Gga proteins, however, partners binding to its VHS domain have remained elusive and Gga localization does not absolutely depend on Arf. Here, we demonstrate that yeast Gga recruitment relies on a network of interactions between the scaffold Ysl2p/Mon2p, the small GTPase Arl1p, and the flippase Neo1p. Deletion of either YSL2 or ARL1 causes mislocalization of Gga2p, whereas a neo1-69 mutant accumulates Gga2p on aberrant structures. Remarkably, Ysl2p directly interacts with human and yeast Ggas through the VHS domain, and binding to Gga proteins is also found for the human Ysl2p orthologue hMon2. Thus, Ysl2p represents an essential, evolutionarily conserved member of a network controlling direct binding and membrane docking of Ggas. Because activated Arl1p is part of the network that binds Gga2p, Arf and Arf-like GTPases may interact in a regulatory cascade.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ADP-Ribosylation Factors / analysis
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ADP-Ribosylation Factors / metabolism*
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Adaptor Proteins, Vesicular Transport / analysis
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Adaptor Proteins, Vesicular Transport / metabolism*
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Adenosine Triphosphatases / genetics
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Adenosine Triphosphatases / metabolism
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Cell Line
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Endosomes / chemistry
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Endosomes / metabolism
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Gene Deletion
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Humans
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Membrane Transport Proteins / genetics
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Membrane Transport Proteins / metabolism
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Monomeric GTP-Binding Proteins / genetics
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Monomeric GTP-Binding Proteins / metabolism
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Phospholipid Transfer Proteins
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Protein Structure, Tertiary
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Proton-Translocating ATPases / metabolism*
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Saccharomyces cerevisiae Proteins / analysis
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism*
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Vesicular Transport Proteins / genetics
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Vesicular Transport Proteins / metabolism
Substances
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Adaptor Proteins, Vesicular Transport
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GGA adaptor proteins
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Gga2 protein, S cerevisiae
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MON2 protein, S cerevisiae
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MON2 protein, human
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Membrane Transport Proteins
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Phospholipid Transfer Proteins
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Saccharomyces cerevisiae Proteins
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Vesicular Transport Proteins
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ARL1 protein, S cerevisiae
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Adenosine Triphosphatases
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Proton-Translocating ATPases
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ADP-Ribosylation Factors
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Monomeric GTP-Binding Proteins
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NEO1 protein, S cerevisiae