Src-inducible association of CrkL with procaspase-8 promotes cell migration |
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Authors: | Ryon Graf Simone Barbero Nadine Keller Lauren Chen Sean Uryu David Schlaepfer Dwayne Stupack |
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Affiliation: | 1.Department of Reproductive Medicine; Division of Gynecologic Oncology; University of California San Diego School of Medicine; La Jolla, CA USA;2.The UCSD Moores Cancer Center; La Jolla, CA USA;3.Graduate School of Biomedical Sciences, Sanford-Burnham Medical Research Institute, La Jolla, CA USA |
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Abstract: | Procaspase-8, the zymogen form of the apoptosis-initiator caspase-8, undergoes phosphorylation following integrin-mediated cell attachment to an extracellular matrix substrate. Concordant with cell attachment to fibronectin, a population of procaspase-8 becomes associated with a peripheral insoluble compartment that includes focal complexes and lamellar microfilaments. Phosphorylation of procaspase-8 both impairs its maturation to the proapoptotic form and can promote cell migration. Here we show that the cytoskeletal adaptor protein CrkL promotes caspase-8 recruitment to the peripheral spreading edge of cells, and that the catalytic domain of caspase-8 directly interacts with the SH2 domain of CrkL. We show that the interaction is abolished by shRNA-mediated silencing of Src, in Src-deficient MEFs, and by pharmacologic inhibitors of the kinase. The results provide insight into how tyrosine kinases may act to coordinate the suppression caspase-8 mediated apoptosis, while promoting cell invasion. |
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Keywords: | caspase 8 Crk-L Crk Src FAK phosphorylation |
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