title: v-Src tyrosine phosphorylation of connexin43: regulation of gap junction communication and effects on cell transformation.
abstract: The oncogenic tyrosine kinase, v-Src, phosphorylates connexin43 (Cx43) on Y247 and Y265 and inhibits Cx43 gap junctional communication (GJC), the process of intercellular exchange of ions and metabolites. To test the role of a negative charge on Cx43 induced by tyrosine phosphorylation, we expressed Cx43 with glutamic acid substitutions at Y247 or Y265. The Cx43Y247E or Cx43Y265E channels were functional in Cx43 knockout fibroblasts, indicating that introducing a negative charge on Cx43 was not likely the mechanism for v-Src disruption of GJC. Cells coexpressing v-Src and the triple serine to alanine mutant, Cx43S255/279/282A, confirmed that mitogen-activated protein (MAP) kinase phosphorylation of Cx43 was not required for v-Src-induced disruption of GJC and that tyrosine phosphorylation was sufficient. In addition, v-Src cells containing v-Src-resistant gap junctions, Cx43Y247/265F, displayed properties of cell migration, adhesion, and proliferation similar to Cx43wt/v-Src cells, suggesting that Cx43 tyrosine phosphorylation and disruption of GJC are not involved in these transformed cell properties.
authors.affiliation: Department of Immunology, The Scripps Research Institute, La Jolla, California, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Lin
authors.forename: Kendra D
authors.initials: KD
authors.lastname: Martyn
authors.forename: Carrie V
authors.initials: CV
authors.lastname: Guyette
authors.forename: Alan F
authors.initials: AF
authors.lastname: Lau
authors.forename: Bonnie J
authors.initials: BJ
authors.lastname: Warn-Cramer
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics / Q000502:physiology; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D002478:Cells, Cultured; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism*; D017629:Gap Junctions / Q000378:metabolism*; D005786:Gene Expression Regulation; D008954:Models, Biological; D050505:Mutant Proteins / Q000378:metabolism; D015688:Oncogene Protein pp60(v-src) / Q000378:metabolism* / Q000502:physiology*; D010766:Phosphorylation; D051381:Rats
chemical_list: D018031:Connexin 43; D050505:Mutant Proteins; D015688:Oncogene Protein pp60(v-src)