The structure of the GGA1-GAT domain reveals the molecular basis for ARF binding and membrane association of GGAs.
The GGAs are a family of clathrin adaptor proteins involved in vesicular transport between the trans-Golgi network and endosomal system. Here we confirm reports that GGAs are targeted to the Golgi via interaction between the GGA-GAT domain and ARF-GTP, and we present the structure of the GAT domain of human GGA1, completing the structural description of the folded domains of GGA proteins. The GGA-GAT domain possesses an all alpha-helical fold with a "paper clip" topology comprising two independent subdomains. Structure-based mutagenesis demonstrates that ARF1-GTP binding by GGAs is exclusively governed by the N-terminal "hook" subdomain, and, using an in vitro recruitment assay, we show that ARF-GTP binding by this small structure is required and sufficient for Golgi targeting of GGAs.
Collins
Brett M
BM
Department of Clinical Biochemistry, University of Cambridge, Hills Road, CB2 2XY, Cambridge, United Kingdom. bmc25@cam.ac.uk
Watson
Peter J
PJ
Owen
David J
DJ
D020823:ADP-Ribosylation Factor 1 / Q000378:metabolism*; D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D033942:Adaptor Proteins, Vesicular Transport; D000595:Amino Acid Sequence / Q000502:physiology; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002451:Cell Compartmentation / Q000502:physiology; D002478:Cells, Cultured; D022163:Clathrin-Coated Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D005057:Eukaryotic Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000502:physiology*; D051381:Rats; D013552:Swine; D021601:trans-Golgi Network / Q000378:metabolism* / Q000648:ultrastructure
D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; C407306:GGA adaptor proteins; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors