title: The N2-Src neuronal splice variant of C-Src has altered SH3 domain ligand specificity and a higher constitutive activity than N1-Src.
abstract: N2-Src is a poorly understood neuronal splice variant of the ubiquitous C-Src tyrosine kinase, containing a 17 amino acid insert in its Src homology 3 (SH3) domain. To characterise the properties of N2-Src we directly compared its SH3 domain specificity and kinase activity with C- and N1-Src in vitro. N2- and N1-Src had a similar low affinity for the phosphorylation of substrates containing canonical C-Src SH3 ligands and synaptophysin, an established neuronal substrate for C-Src. N2-Src also had a higher basal kinase activity than N1- and C-Src in vitro and in cells, which could be explained by weakened intramolecular interactions. Therefore, N2-Src is a highly active kinase that is likely to phosphorylate alternative substrates to C-Src in the brain.
authors.affiliation: Department of Biology and Hull York Medical School, University of York, Wentworth Way, York YO10 5DD, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Keenan
authors.affiliation: Department of Biology and Hull York Medical School, University of York, Wentworth Way, York YO10 5DD, UK.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Lewis
authors.affiliation: Department of Biology and Hull York Medical School, University of York, Wentworth Way, York YO10 5DD, UK.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Wetherill
authors.affiliation: Department of Biology and Hull York Medical School, University of York, Wentworth Way, York YO10 5DD, UK.
authors.forename: Christopher J R
authors.initials: CJ
authors.lastname: Dunning
authors.affiliation: Department of Biology and Hull York Medical School, University of York, Wentworth Way, York YO10 5DD, UK. Electronic address: gareth.evans@york.ac.uk.
authors.forename: Gareth J O
authors.initials: GJ
authors.lastname: Evans
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D045744:Cell Line, Tumor; D008024:Ligands; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing; D051381:Rats; D017386:Sequence Homology, Amino Acid; D018909:src Homology Domains
chemical_list: D008024:Ligands; D020033:Protein Isoforms; D016392:Proto-Oncogene Proteins pp60(c-src)
keywords: Enzyme kinetics; Kinase assay; Splice variant; Src; Src homology 3 domain; Tyrosine protein kinase