The Fer tyrosine kinase is necessary for platelet-derived growth factor-BB-induced Stat3 phosphorylation and colony formation in soft agar
(English)Manuscript (preprint) (Other academic)
Fer is a cytoplasmic tyrosine kinase that is activated in response to platelet-derived growth factor (PDGF) stimulation. In the present report, we show that Fer associates with the activated PDGF b-receptor (PDGFRb) through multiple autophosphorylation sites, i.e. Tyr579, Tyr581, Tyr740 and Tyr1021. Using low molecular weight inhibitors we found that PDGF-BB-induced Fer activation is dependent on PDGFRb kinase activity, but not on the enzymatic activity of Src or Jak kinases. To elucidate the function of Fer downstream of PDGFRb, we downregulated the expression using siRNA; under conditions with reduced Fer expression, PDGF-BB was unable to induce phosphorylation of Stat3, whereas Stat5, Erk1/2 and Akt were unaffected. In addition, PDGFRb autophosphorylation was partially dependent on Fer expression. On a functional level, we could demonstrate that expression of Fer is dispensable for PDGF-BB-induced proliferation and migration. However, Fer was found to be essential for colony formation in soft agar, consistent with its critical role in Stat3 activation, which has frequently been implicated in cell transformation.
Biochemistry and Molecular Biology
Research subject Biology with specialization in Molecular Cell Biology
IdentifiersURN: urn:nbn:se:uu:diva-122467OAI: oai:DiVA.org:uu-122467DiVA: diva2:310210