tailieunhanh - Báo cáo khoa học: Roles of the SH2 and SH3 domains in the regulation of neuronal Src kinase functions

Previous studies demonstrated that intra-domain interactions between Src family kinases (SFKs), stabilized by binding of the phosphorylated C-terminus to the SH2 domain and⁄or binding of the SH2 kinase linker to the SH3 domain, lock the molecules in a closed conformation, disrupt the kinase active site, and inactivate SFKs. | IFEBS Journal Roles of the SH2 and SH3 domains in the regulation of neuronal Src kinase functions Bradley R. Groveman1 Sheng Xue2 Vedrana Marin1 Jindong Xu2 Mohammad K. Ali1 Ewa A. Bienkiewicz1 and Xian-Min Yu1 2 1 Department of BiomedicalSciences College of Medicine Florida State University Tallahassee USA 2 Faculty of Dentistry University of Toronto Ontario Canada Keywords NMDA receptor regulation phosphorylation Src the SH2 domain the SH3 domain Correspondence . Yu 1115 West Call Street Tallahassee FL 32306-4300 USA Fax 1 850 644 5781 Tel 1 850 645 2718 E-mail Received 10 September 2010 revised 3 November 2010 accepted 6 December 2010 doi Previous studies demonstrated that intra-domain interactions between Src family kinases SFKs stabilized by binding of the phosphorylated C-terminus to the SH2 domain and or binding of the SH2 kinase linker to the SH3 domain lock the molecules in a closed conformation disrupt the kinase active site and inactivate SFKs. Here we report that the up-regulation of N-methyl-D-aspartate receptors NMDARs induced by expression of constitutively active neuronal Src n-Src in which the C-terminus tyrosine is mutated to phenylalanine n-Src Y535F is significantly reduced by dysfunctions of the SH2 and or SH3 domains of the protein. Furthermore we found that dysfunctions of SH2 and or SH3 domains reduce autophosphorylation of the kinase activation loop depress kinase activity and decrease NMDAR phosphorylation. The SH2 domain plays a greater regulatory role than the SH3 domain. Our data also show that n-Src binds directly to the C-terminus of the NMDAR NR2A subunit in vitro with a KD of nM. This binding is not Src kinase activity-dependent and dysfunctions of the SH2 and or SH3 domains do not significantly affect the binding. These data indicate that the SH2 and SH3 domains may function to promote the catalytic activity of active n-Src which is important in the regulation .