Affiliation:
1. Department of Neurochemistry, Institute of Neurology, London WC1N 1PJ, United Kingdom
2. Glaxo-IMCB Group, Institute of Molecular and Cell Biology, Singapore 119076
Abstract
Cdc42Hs is involved in cytoskeletal reorganization and is required for neurite outgrowth in N1E-115 cells. To investigate the molecular mechanism by which Cdc42Hs regulates these processes, a search for novel Cdc42Hs protein partners was undertaken by yeast two-hybrid assay. Here, we identify the 58-kD substrate of the insulin receptor tyrosine kinase (IRS-58) as a Cdc42Hs target. IRS-58 is a brain-enriched protein comprising at least four protein–protein interaction sites: a Cdc42Hs binding site, an Src homology (SH)3-binding site, an SH3 domain, and a tryptophan, tyrptophan (WW)-binding domain. Expression of IRS-58 in Swiss 3T3 cells leads to reorganization of the filamentous (F)-actin cytoskeleton, involving loss of stress fibers and formation of filopodia and clusters. In N1E-115 cells IRS-58 induces neurite outgrowth with high complexity. Expression of a deletion mutant of IRS-58, which lacks the SH3- and WW-binding domains, induced neurite extension without complexity in N1E-115 cells. In Swiss 3T3 cells and N1E-115 cells, IRS-58 colocalizes with F-actin in clusters and filopodia. An IRS-581267N mutant unable to bind Cdc42Hs failed to localize with F-actin to induce neurite outgrowth or significant cytoskeletal reorganization. These results suggest that Cdc42Hs facilitates cytoskeletal reorganization and neurite outgrowth by localizing protein complexes via adaptor proteins such as IRS-58 to F-actin.
Publisher
Rockefeller University Press
Reference49 articles.
1. The insulin receptor tyrosine kinase substrate p58/p53 and the insulin receptor are components of CNS synapses;Abbot;J. Neurosci.,1999
2. Breakpoint cluster region gene product-related domain of n-chimaerin. Discrimination between Rac-binding and the GTPase-activating residues by mutational analysis;Ahmed;J. Biol. Chem.,1994
3. GAP activity of n-chimaerin and effect of lipids;Ahmed;Methods Enzymol.,1995
4. Cdc42 and Rac effectors; ACK, PAK, WASP, MRCK, n-chimaerin, POR1 and p67phox;Ahmed,1998
5. A Cdc42 target protein with homology to the non-kinase domain of FER has a potential role in regulating the actin cytoskeleton;Aspenstrom;Curr. Biol.,1997
Cited by
147 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献