Inactivation of a MAPK-like protein kinase and activation of a MBP kinase in germinating barley embryos

We provide evidence for involvement of tao different 45 kDa protein kinases in rehydration and germination of barley embryos. In dry embryos, a myelin basic protein (MBP) phosphorylating kinase was detected, which could be im munoprecipitated with an anti-MAPK (mitogen-activated protein kinase) antib ody, Rehydration of the embryo induced a decrease in activity of this 45 kD a MAPK-like protein kinase, In addition, activity of a MBP kinase of the sa me molecular weight was subsequently found to be induced, This second MBP k inase activity could not be immunoprecipitated with the anti-MAPK antibody and was induced only in germinating embryos, not in dormant embryos, (C) 20 00 Federation of European Biochemical Societies. Published by Elsevier Scie nce B.V. All rights reserved.