PERVANADATE ELICITS PROLIFERATION AND MEDIATES ACTIVATION OF MITOGEN-ACTIVATED PROTEIN (MAP) KINASE IN THE NUCLEUS

There is growing evidence for the role of protein tyrosine phosphatase s in controlling such fundamental cellular processes as growth and dif ferentiation. Pervanadate is a potent inhibitor of protein tyrosine ph osphatase which has been observed here to induce proliferation in C3H1 0T1/2 mouse fibroblasts, Pervanadate also translocated/activated p42/4 4 mitogen-activated protein (MAP) kinase to the cell nucleus, An almos t similar pattern of nuclear p42/44 MAP kinase stimulation is seen wit h TPA. On the other hand, TPA treatment results in a rapid activation of cytosolic MAP kinase which declines with time. Thus pervanadate app ears as a very useful tool for studying tyrosine phosphorylation. (C) 1997 Federation of European Biochemical Societies.