Roles and regulation of serine/threonine-specific protein phosphatases in the cell cycle.

Abstract

As cell cycle research enters its fourth decade, multiple protein kinases are firmly established as key regulators of the cell cycle, and some of them have emerged as promising drug targets. This review will discuss the serine/threonine-specific protein phosphatases that oppose the actions of protein kinases. Typically, a phosphatase may stimulate one cell cycle transition, and inhibit another; alternatively, two different phosphatase holoenzymes may have opposing effects on the same cell cycle transition. Thus, both activation and inhibition of these enzymes could result in cell cycle arrest and/or apoptosis. Specific findings, the challenges and approaches to exploit this potential will be discussed.