Cellular signaling events elicited by v-abl associated with growth factor independence in an interleukin-3-dependent cell line.

OWEN, P J and MUSK, P and EVANS, C A and WHETTON, A D (1993) Cellular signaling events elicited by v-abl associated with growth factor independence in an interleukin-3-dependent cell line. Journal of Biological Chemistry, 268 (21). pp. 15696-15703. ISSN 0021-9258

Abstract

A temperature-sensitive mutant of the v-abl oncoprotein has previously been shown to have markedly reduced tyrosine protein kinase activity in interleukin 3 (IL-3)-dependent cells grown at restrictive (39-degrees-C), compared to permissive (32-degrees-C) temperatures. Transfection of this mutant v-abl into the IC2.9 cell line, generated the IC.DP subclone which was dependent on IL-3 for survival at 39-degrees-C, but not at 32-degrees-C. Furthermore, IC.DP cells cultured at 32-degrees-C exhibited IL-3-independent thymidine incorporation, which was not apparent at 39-degrees-C. Switching cells from the restrictive to the permissive temperature resulted in an increase in cellular inositol-1,4,5-trisphosphate, choline phosphate and diacylglycerol levels in the IC.DP cell line. These increases were only observed after a lag period of 4 h. Within 2 h of switching IC.DP cells previously maintained at 32 to 39-degrees-C, there was a significant decrease in all three metabolites. Temperature switches had no effect upon these metabolites in the parent IC2.9 cell line. Down-regulation of protein kinase C inhibited v-abl-stimulated DNA synthesis in IC.DP cells cultured at 32-degrees-C. IC.DP cells cultured at 32-degrees-C were found to have a constitutively activated Na+/H+ antiport, although this activation was inhibited by the down-modulation of protein kinase C. These data indicate a role for phospholipid hydrolysis and protein kinase C activation in V-ABL-mediated abrogation of IL-3 dependence.