The Control of Plant Growth by Protein Kinases
A substantial majority of animal hormones have their biological effects mediated by theadenyl cyclase system (1)0 Until Kuo and Greengard (2) produced their unifying theory it was not clear how cyclic AMP initiated the subsequent molecular events associated with hormone action. Their theory (2.) proposed that the effects of cyclic AMP were mediated by cyclic AMP-dependent protein kinases in the responsive tissue. Since it is the catalytic function of protein kinases to phosphorylate proteins, this theory places our understanding of hormone action firmly on knowing which cellular proteins are phosphorylated. The list of known phosphorylated protein is very extensive and covers proteins in all of the major cellular groups (3). Evidence that phosphorylation (or dephos-phorylation) modifies the biological activity of the phosphorylated protein has however only been critically demonstrated in a few cases (3). Despite the apparent absence of cyclic AMP in plants, this field of research offers such considerable promise for dissecting out the regulatory systems of plants that its study can hardly be avoided.
KeywordsAbscisic Acid Mineral Salt Medium DEAE Cellulose Chromatin Protein Barley Embryo
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- 3.Trewavas, A. J. 1976. Ann. Rev. Plant Physiol. (in press)Google Scholar
- 8.Lake, R. G. 1973. Nature 242: 1 45.Google Scholar
- 9.Yeoman, M. M., and Evans, P. K. 1967. Ann. Bot. 31: 323.Google Scholar
- 10.Langan, T. A. and Hohmann, P. 1974. Fed. Proc. 33: 1597.Google Scholar
- 15.Blakeley, L. Personal communication.Google Scholar