Transient activation of Ras-dependent signalling at the early stages of Herbimycin A induced erythroid differentiation of human K562 cells.

Aim: To study the dynamics of Ras-dependent signalling in the course of Herbimycin A induced erythroid differentiation of human erythroleukemia K562 cells.

Methods: p21Ras functional activity was analyzed by direct measurement of GTP/GDP ratio in anti-p21Ras immunoprecipitates of K562 cells previously incubated with H3(32)PO4. Dynamics of protein tyrosine phosphorylation was studied using Western blotting.