INHIBITORS OF PROTEIN PHOSPHATASE-1 AND PHOSPHATASE-2A - 2 OF THE MAJOR SERINE THREONINE PROTEIN PHOSPHATASES INVOLVED IN CELLULAR-REGULATION

The broad specificity type-1 and type-2A protein phosphatases (PP-1 an d PP-2A) have emerged as important enzymes in the regulation of eukary otic cell function. Over the past few years an ever increasing array o f potent inhibitor molecules of the catalytic subunits of PP-1 and -2A (PP-1c and PP-2Ac) have been described. These inhibitors are structur ally diverse and found in organisms from prokaryote and protist to mul ticellular eukaryote. This review will focus on recent advances in und erstanding the structure and properties of these inhibitors and how th ey may be involved in regulating PP-1c and PP-2Ac in vivo.