GROWTH-FACTORS AND MITOGEN-ACTIVATED PROTEIN-KINASES

Mammalian cells respond to external stimuli by activation of a variety of signal transduction pathways, which culminate in stereotypical res ponses, such as proliferation, growth arrest, hypertrophy, differentia tion, or apoptosis. In vertebrates the actions of many stimuli resulti ng in proliferative or hypertrophic growth converge on a set of cellul ar kinase cascades, which are collectively called the mitogen-activate d protein (MAP) kinase cascades. These MAP kinases have been implicate d in vascular smooth muscle cell proliferation and hypertrophy, respon ses that are central to the pathophysiology of hypertension. In this r eview, we will examine how proliferative and hypertrophic stimuli acti vate these MAP kinase cascades, what are the consequences of that acti vation on gene expression, and how do these signals drive the cell int o one of the stereotypical responses noted above.