The Brain Research Centre, Division of Neurology, 2211 Wesbrook Mall, University of British Columbia, Vancouver, BC V6T 2B5, Canada. spelech@kinexus.ca
The closely related mitogen-activated protein kinases ERK1 and ERK2 have now been shown to have opposing roles in Ras-mediated cell proliferation. I propose that dimerization of these highly related protein kinases could underlie these surprising observations and that this could be a common paradigm for widespread regulation of protein phosphorylation by kinase-substrate interactions.