Protein phosphorylation and signal transduction

It is now generally accepted that protein phosphorylation-dephosphorylation has a role in the regulation of essentially all cellular functions. Thus, it is of interest that this process is involved in signal transduction. Non etheless, the extent to which protein phosphorylation participates in signa ling is truly remarkable. Almost every known signaling pathway eventually i mpinges on a protein kinase, or in some instances, a protein phosphatase. T he diversity of these enzymes is noteworthy, and it is of interest that man y biotechnology companies are eyeing them as potentially important targets for drugs. Such drugs may have important therapeutic applications, and in a ny event, they certainly will be useful to investigators who study signal t ransduction. Indeed, this already has been proven to be true. (C) 1999 Else vier Science Inc. All rights reserved.