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Publication Abstract from PubMed

Different assemblies of accessory proteins with clathrin are critical for transporting precisely various cargos between intracellular compartments. GGA proteins are adaptors for clathrin-mediated intracellular trafficking, connecting other accessory and cargo proteins to clathrin-coated vesicles. Both binding to the GAE domain of GGA protein yGGA2 in Saccharomyces cerevisia, Ent3 and Ent5 are involved in different trafficking pathways. Ent5 is ubiquitous and localized in a manner independent of yGGA2, and Ent3 functions preferentially through yGGA2. Not known are the sources of these differences. Here we show not all acidic-phenylalanine motifs in Ent3/5 are active for yGGA2_GAE domain binding. Two of the three acidic-phenylalanine motifs from Ent3 can bind to the yGGA2_GAE domain, while only one of the two motifs from Ent5 can bind. We also determined the crystal structure of the yGGA2_GAE domain at 1.8 A resolution. Structural docking and mutagenesis analysis shows inactive motifs in Ent3 and Ent5 repel yGGA2_GAE binding through disfavored residues at positions 1 and 3. These results suggest accessory proteins may fine-tune the GGA adaptor dependence by adjusting their non-acidic-phenylalanine residues, thus contributing to the distinct role of Ent3 and Ent5 in trafficking.

Structural basis for the specificity of the GAE domain of yGGA2 for its accessory proteins Ent3 and Ent5 .,Fang P, Li X, Wang J, Niu L, Teng M Biochemistry. 2010 Sep 14;49(36):7949-55. PMID:20704189^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.