Structural highlights
Function
GIT1_RAT GTPase-activating protein for the ADP ribosylation factor family. May serve as a scaffold to bring together molecules to form signaling modules controlling vesicle trafficking, adhesion and cytoskeletal organization. Increases the speed of cell migration, as well as the size and rate of formation of protrusions, possibly by targeting PAK1 to adhesions and the leading edge of lamellipodia. Sequesters inactive non-tyrosine-phosphorylated paxillin in cytoplasmic complexes.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The G protein-coupled receptor kinase-interacting protein 1 (GIT1) is a multidomain protein that plays an important role in cell adhesion, motility, cytoskeletal remodeling, and membrane trafficking. GIT1 mediates the localization of the p21-activated kinase (PAK) and PAK-interactive exchange factor to focal adhesions, and its activation is regulated by the interaction between its C-terminal paxillin-binding domain (PBD) and the LD motifs of paxillin. In this study, we determined the solution structure of rat GIT1 PBD by NMR spectroscopy. The PBD folds into a four-helix bundle, which is structurally similar to the focal adhesion targeting and vinculin tail domains. Previous studies showed that GIT1 interacts with paxillin through the LD4 motif. Here, we demonstrated that in addition to the LD4 motif, the GIT1 PBD can also bind to the paxillin LD2 motif, and both LD2 and LD4 motifs competitively target the same site on the PBD surface. We also revealed that paxillin Ser(272) phosphorylation does not influence GIT1 PBD binding in vitro. These results are in agreement with the notion that phosphorylation of paxillin Ser(272) plays an essential role in regulating focal adhesion turnover.
GIT1 paxillin-binding domain is a four-helix bundle, and it binds to both paxillin LD2 and LD4 motifs.,Zhang ZM, Simmerman JA, Guibao CD, Zheng JJ J Biol Chem. 2008 Jul 4;283(27):18685-93. Epub 2008 Apr 30. PMID:18448431[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Zhang ZM, Simmerman JA, Guibao CD, Zheng JJ. GIT1 paxillin-binding domain is a four-helix bundle, and it binds to both paxillin LD2 and LD4 motifs. J Biol Chem. 2008 Jul 4;283(27):18685-93. Epub 2008 Apr 30. PMID:18448431 doi:10.1074/jbc.M801274200
