1ki1
From Proteopedia
Guanine Nucleotide Exchange Region of Intersectin in Complex with Cdc42
Structural highlights
Function[CDC42_HUMAN] Plasma membrane-associated small GTPase which cycles between an active GTP-bound and an inactive GDP-bound state. In active state binds to a variety of effector proteins to regulate cellular responses. Involved in epithelial cell polarization processes. Regulates the bipolar attachment of spindle microtubules to kinetochores before chromosome congression in metaphase. Plays a role in the extension and maintenance of the formation of thin, actin-rich surface projections called filopodia. Mediates CDC42-dependent cell migration.[1] [2] [3] [ITSN1_HUMAN] Adapter protein that may provide indirect link between the endocytic membrane traffic and the actin assembly machinery. May regulate the formation of clathrin-coated vesicles. Involved in endocytosis of integrin beta-1 (ITGB1) and transferrin receptor (TFR); internalization of ITGB1 as DAB2-dependent cargo but not TFR may involve association with DAB2. Isoform 1 could be involved in brain-specific synaptic vesicle recycling. Inhibits ARHGAP31 activity toward RAC1.[4] [5] 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 PubMedActivation of Rho-family GTPases involves the removal of bound GDP and the subsequent loading of GTP, all catalyzed by guanine nucleotide exchange factors (GEFs) of the Dbl-family. Despite high sequence conservation among Rho GTPases, Dbl proteins possess a wide spectrum of discriminatory potentials for Rho-family members. To rationalize this specificity, we have determined crystal structures of the conserved, catalytic fragments (Dbl and pleckstrin homology domains) of the exchange factors intersectin and Dbs in complex with their cognate GTPases, Cdc42 and RhoA, respectively. Structure-based mutagenesis of intersectin and Dbs reveals the key determinants responsible for promoting exchange activity in Cdc42, Rac1 and RhoA. These findings provide critical insight into the structural features necessary for the proper pairing of Dbl-exchange factors with Rho GTPases and now allow for the detailed manipulation of signaling pathways mediated by these oncoproteins in vivo. Structural basis for the selective activation of Rho GTPases by Dbl exchange factors.,Snyder JT, Worthylake DK, Rossman KL, Betts L, Pruitt WM, Siderovski DP, Der CJ, Sondek J Nat Struct Biol. 2002 Jun;9(6):468-75. PMID:12006984[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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