Kim S, et al. (2003) The GIT family of proteins forms multimers and associates with the presynaptic cytomatrix protein Piccolo. J Biol Chem 278(8):6291-300
Abstract: The cytoskeletal matrix assembled at active zones (CAZ) is implicated in defining neurotransmitter release sites. However, little is known about the molecular mechanisms by which the CAZ is organized. Here we report a novel interaction between Piccolo, a core component of the CAZ, and GIT proteins, multidomain signaling integrators with GTPase-activating protein activity for ADP-ribosylation factor small GTPases. A small region (approximately 150 amino acid residues) in Piccolo, which is not conserved in the closely related CAZ protein Bassoon, mediates a direct interaction with the Spa2 homology domain (SHD) domain of GIT1. Piccolo and GIT1 colocalize at synaptic sites in cultured neurons. In brain, Piccolo forms a complex with GIT1 and various GIT-associated proteins, including betaPIX, focal adhesion kinase, liprin-alpha, and paxillin. Point mutations in the SHD of GIT1 differentially interfere with the association of GIT1 with Piccolo, betaPIX, and focal adhesion kinase, suggesting that these proteins bind to the SHD by different mechanisms. Intriguingly, GIT proteins form homo- and heteromultimers through their C-terminal G-protein-coupled receptor kinase-binding domain in a tail-to-tail fashion. This multimerization enables GIT1 to simultaneously interact with multiple SHD-binding proteins including Piccolo and betaPIX. These results suggest that, through their multimerization and interaction with Piccolo, the GIT family proteins are involved in the organization of the CAZ.
|Status: Published||Type: Journal Article||PubMed ID: 12473661|
Topics addressed in this paper
- To find other papers on a gene and topic, click on the colored ball in the appropriate box.
- displays other papers with information about that topic for that gene.
- displays other papers in SGD that are associated with that topic.
The topic is addressed in these papers but does not describe a specific gene or chromosomal feature.
- To go to the Locus page for a gene, click on the gene name.
|Topics||Genes linked to topics|
|Non-Fungal Related Genes/Proteins|