Regulation of RhoGEF Activity by Intramolecular and Intermolecular SH3 Domain Interactions

Department of Molecular, Microbial and Structural Biology, University of Connecticut, Сторс, Connecticut, United States
Journal of Biological Chemistry (Impact Factor: 4.57). 08/2006; 281(27):18774-86. DOI: 10.1074/jbc.M512482200
Source: PubMed


RhoGEFs are central controllers of small G-proteins in cells and are regulated by several mechanisms. There are at least 22
human RhoGEFs that contain SH3 domains, raising the possibility that, like several other enzymes, SH3 domains control the
enzymatic activity of guanine nucleotide exchange factor (GEF) domains through intra- and/or intermolecular interactions.
The structure of the N-terminal SH3 domain of Kalirin was solved using NMR spectroscopy, and it folds much like other SH3
domains. However, NMR chemical shift mapping experiments showed that this Kalirin SH3 domain is unique, containing novel cooperative
binding site(s) for intramolecular PXXP ligands. Intramolecular Kalirin SH3 domain/ligand interactions, as well as binding of the Kalirin SH3 domain to the adaptor
protein Crk, inhibit the GEF activity of Kalirin. This study establishes a novel molecular mechanism whereby intramolecular
and intermolecular Kalirin SH3 domain/ligand interactions modulate GEF activity, a regulatory mechanism that is likely used
by other RhoGEF family members.

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Available from: Martin R Schiller, Nov 12, 2015
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    • "pGEX.GST-KGEF1, -KGEF1→7end and its mutants were purified as described (Alam et al., 1997; Penzes et al., 2001; Schiller et al., 2006). The pGEX-GST-Rac1 vector was a gift from Dr. Richard Cerione (Cornell University). "
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