p56/p53lyn tyrosine kinase activation in mammalian cells treated with mitomycin C
Kharbanda, S.; Yuan, Z.M.; Taneja, N.; Weichselbaum, R.; Kufe, D.
Oncogene 9(10): 3005-3011
1994
ISSN/ISBN: 0950-9232 PMID: 8084605 Document Number: 432107
The present studies have examined the effects of mitomycin C (MMC), a genotoxic alkylating agent, on the activation of Src-like protein tyrosine kinases in HL-60 myeloid leukemia cells. The results demonstrate no detectable induction of p59-fyn or pp60-c-src activity. The response of HL-60 cells to MMC however was associated with rapid activation of p56/p53-lyn. Similar findings were obtained with other alkylating agents such as nitrogen mustard and cis-platinum. Activation of p56/ p53-lyn was associated with increased autophosphorylation on tyrosine and sensitivity to the tyrosine kinase inhibitors herbimycin A and genistein. Studies with a glutathione S-transferase-Lyn fusion protein were performed to explore the potential significance of p56/ p53-lyn activation. Analysis of the adsorbates demonstrates interaction of Lyn with the cell cycle regulatory protein, p34-cdc2. Coimmunoprecipitation studies further confirmed the association of p56/p53-lyn and p34-cdc2 in MMC-treated cells. We also demonstrate that p34-cdc2 undergoes increased phosphorylation on tyrosine following MMC exposure and that p56/p53-lyn phosphorylates the Tyr-15 site of p34-cdc2 in vitro. These findings indicate that the cellular response to MMC includes activation of p56/ p53-lyn and that this event may contribute to signals transduced by the DNA damage-dependent mitotic checkpoint.