THE C-SRC TYROSINE KINASE (CSK) GENE, A POTENTIAL ANTIONCOGENE, LOCALIZES TO HUMAN-CHROMOSOME REGION 15Q23-]Q25

We have previously reported the cloning of a novel cytoplasmic tyrosine kinase, CSK. This tyrosine kinase has been shown to downregulate the tyrosine kinase activity of the c-src oncoprotein through tyrosine phosphorylation of the c-src carboxyl terminus. Cell transformation by src oncoproteins is caused by several oncogenic mechanisms, which interfere with this phosphorylation. The CSK gene could therefore potentially function as an antioncogene. We have here mapped the CSK gene to 15q23 --> q25 by in situ hybridization.