title: An active Src kinase-beta-actin association is linked to actin dynamics at the periphery of colon cancer cells.
abstract: Src controls the dynamic actin cytoskeleton in fibroblasts and in cancer cells, although it is not known how direct its effects are. Using FRET/FLIM imaging, we found that wild type Src associates directly, or indirectly, with peripheral beta-actin at integrin adhesions after serum stimulation, and that an active Src kinase domain is essential. Beta-actin can be directly tyrosine-phosphorylated by Src in vitro, and in a Src-dependent manner in cells. Moreover, beta-actin dynamics are suppressed when Src is rendered kinase-inactive. Surprisingly, debilitating mutations in the Src SH2 or SH3 domains do not suppress association of Src with beta-actin. This may therefore be an example of a spatially regulated Src kinase/substrate interaction that is controlling peripheral actin dynamics. Interestingly, there is no FRET between Src and beta-actin at cadherin-mediated cell-cell contacts, despite apparent co-localization there, demonstrating precise spatial specificity of Src/beta-actin complexes.
authors.affiliation: The Beatson Institute for Cancer Research, Cancer Research UK Beatson Laboratories, Garscube Estate, Switchback Road, Glasgow G61 1BD, Scotland, UK.
authors.forename: Egle
authors.initials: E
authors.lastname: Avizienyte
authors.forename: Melanie
authors.initials: M
authors.lastname: Keppler
authors.forename: Emma
authors.initials: E
authors.lastname: Sandilands
authors.forename: Valerie G
authors.initials: VG
authors.lastname: Brunton
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Winder
authors.forename: Tony
authors.initials: T
authors.lastname: Ng
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Frame
mesh_terms: D000199:Actins / Q000378:metabolism / Q000502:physiology*; D000595:Amino Acid Sequence; D002450:Cell Communication; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D004789:Enzyme Activation; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D011485:Protein Binding; D015398:Signal Transduction; D018909:src Homology Domains; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; D019061:src-Family Kinases