Electrophoretic forms of protein kinases during differentiation of murine erythroleukaemic cells.

The different forms of cAMP-dependent, cGMP-dependent and cyclic nucleotide-independent protein kinases were studied in relation to hexamethylene bisacetamide (HMBA)-induced differentiation of murine erythroleukaemic cells, using a nondenaturing polyacrylamide gel electrophoresis system. Several forms of histone-dependent kinases were detected and there was a definite change in the relative proportions of the two major components and of minor components in cells treated with HMBA, as compared with untreated controls. The faster-moving of the two major forms, which increased on HMBA stimulation, appeared to be both cAMP and cGMP dependent; the slower moving form, which decreased with HMBA treatment, showed little dependence on either cAMP or cGMP.