1na8

From Proteopedia

Revision as of 14:27, 15 February 2008

Crystal structure of ADP-ribosylation factor binding protein GGA1

Overview

The adaptor appendage domains are believed to act as binding platforms for, coated vesicle accessory proteins. Using glutathione S-transferase, pulldowns from pig brain cytosol, we find three proteins that can bind to, the appendage domains of both the AP-1 gamma subunit and the GGAs:, gamma-synergin and two novel proteins, p56 and p200. p56 elicited better, antibodies than p200 and was generally more tractable. Although p56 and, gamma-synergin bind to both GGA and gamma appendages in vitro, immunofluorescence labeling of nocodazole-treated cells shows that p56, colocalizes with GGAs on TGN46-positive membranes, whereas gamma-synergin, colocalizes with AP-1 primarily on a different membrane compartment., Furthermore, in AP-1-deficient cells, p56 remains membrane-associated, whereas gamma-synergin becomes cytosolic. Thus, p56 and gamma-synergin, show very strong preferences for GGAs and AP-1, respectively, in vivo., However, the GGA and gamma appendages share the same fold as determined by, x-ray crystallography, and mutagenesis reveals that the same amino acids, contribute to their binding sites. By overexpressing wild-type GGA and, gamma appendage domains in cells, we can drive p56 and gamma-synergin, respectively, into the cytosol, suggesting a possible mechanism for, selectively disrupting the two pathways.

About this Structure

1NA8 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

Binding partners for the COOH-terminal appendage domains of the GGAs and gamma-adaptin., Lui WW, Collins BM, Hirst J, Motley A, Millar C, Schu P, Owen DJ, Robinson MS, Mol Biol Cell. 2003 Jun;14(6):2385-98. Epub 2003 Mar 20. PMID:12808037

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