Critical role for DOK1 in PDGF-BB stimulated glioma cell invasion via p130Cas and Rap1 signalling

• Published in: Journal of cell science
• Main Authors: Barrett, Angela, Evans, Ian M, Frolov, Antonina, Britton, Gary, Pellet-Many, Caroline, Yamaji, Maiko, Mehta, Vedanta, Bandophadyay, Rina, Li, Ningning, Brandner, Sebastian, Zachary, Ian C., Frankel, Paul
• Format: Journal Article
• Language: English
• Published: 01.01.2014
• ISSN: 0021-9533; 1477-9137
• DOI: 10.1242/jcs.135988

The mechanisms which regulate tumour cell motility are essential for invasion and metastasis. We report here that PDGF-BB mediated glioma cell invasion and migration are dependent on the adaptor protein Downstream of Kinase 1 (DOK1). DOK1 is expressed in several glioma cell lines, and in tumour biopsies from high grade gliomas. DOK1 becomes tyrosine phosphorylated upon PDGF-BB stimulation of human glioma cells. Knockdown of DOK1, or expression of a DOK1 mutant (DOK1FF) containing Tyr/Phe substitutions at amino acids 362 and 398, resulted in inhibition of PDGF-BB induced p130Cas tyrosine phosphorylation and Rap1 activation. DOK1 co-localises with tyrosine phosphorylated p130Cas at the membrane of PDGF-BB treated cells. Expression of a non-tyrosine phosphorylatable substrate domain mutant of p130Cas (p130Cas15F) inhibited PDGF-BB mediated Rap1 activation. Knockdown of DOK1 and Rap1 expression inhibited PDGF-BB induced chemotactic cell migration, and knockdown of DOK1 and Rap1 expression, and expression of DOK1FF inhibited PDGF mediated 3D spheroid invasion. These data show a critical role for DOK1 in the regulation of PDGF-BB mediated tumour cell motility through a p130Cas/Rap1 signalling pathway.