Gamma-synergin: an EH domain-containing protein that interacts with gamma-adaptin.
The AP-1 adaptor complex is associated with the TGN, where it links selected membrane proteins to the clathrin lattice, enabling these proteins to be concentrated in clathrin-coated vesicles. To identify other proteins that participate in the clathrin-coated vesicle cycle at the TGN, we have carried out a yeast two- hybrid library screen using the gamma-adaptin subunit of the AP-1 complex as bait. Two novel, ubiquitously expressed proteins were found: p34, which interacts with both gamma-adaptin and alpha-adaptin, and gamma-synergin, an alternatively spliced protein with an apparent molecular mass of approximately 110-190 kD, which only interacts with gamma-adaptin. gamma-Synergin is associated with AP-1 both in the cytosol and on TGN membranes, and it is strongly enriched in clathrin-coated vesicles. It binds directly to the ear domain of gamma-adaptin and it contains an Eps15 homology (EH) domain, although the EH domain is not part of the gamma-adaptin binding site. In cells expressing alpha-adaptin with the gamma-adaptin ear, a construct that goes mainly to the plasma membrane, much of the gamma-synergin is also rerouted to the plasma membrane, indicating that it follows AP-1 onto membranes rather than leading it there. The presence of an EH domain suggests that gamma-synergin links the AP-1 complex to another protein or proteins.
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L J
LJ
Department of Clinical Biochemistry and Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 2XY, England.
Sowerby
P J
PJ
Lui
W W
WW
Robinson
M S
MS
D033961:Adaptor Protein Complex 1; D033965:Adaptor Protein Complex alpha Subunits; D033982:Adaptor Protein Complex gamma Subunits; D033942:Adaptor Proteins, Vesicular Transport; D017398:Alternative Splicing / Q000235:genetics; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D003600:Cytosol / Q000378:metabolism; D004285:Dogs; D029721:Drosophila Proteins; D006056:Golgi Apparatus / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D015003:Yeasts / Q000235:genetics
D033961:Adaptor Protein Complex 1; D033965:Adaptor Protein Complex alpha Subunits; D033982:Adaptor Protein Complex gamma Subunits; D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; D029721:Drosophila Proteins; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C498482:Synrg protein, rat; C121511:msps protein, Drosophila