Regulation of cell function by protein kinases and phosphatases.
The process of reversible protein phosphorylation-dephosphorylation is an important mechanism for the regulation of a numerous cellular processes. The extent of phosphorylation of specific proteins is determined by the relative activity of protein kinases and protein phosphatases. In many cases, the relevant kinase has been identified. However, our understanding of the regulation of the phosphorylation-dephosphorylation mechanism has been hindered by a lack of information about the protein phosphatases involved. For a number of years, my laboratory has been interested in the enzymology of protein kinases and protein phosphatases. Our past accomplishments have included the discovery of calcium and cyclic nucleotide-independent glycogen synthase kinases that phosphorylate and inactivate glycogen synthase and a class of protein phosphatase which is stimulated by polycations (now designated phosphatase 2A). More recently we have discovered a novel form of protein phosphatase 1 in heart muscle and a latent form of phosphatase 2A in skeletal muscle.
