<b>Inhibition of protein serine/threonine phosphatases directly induces premature chromosome condensation in mammalian somatic </b><b>cells </b>

Abstract

Chromosomes usually condense during mitosis, but condensation may be uncoupled from mitotic events under certain circumstances. This phenomenon is known as premature chromosome condensation (PCC). Here we show that 100 nM okadaic acid or calyculin A can induce PCC at any time during the cell cycle of several types of mammalian cells; G1-, S-and G2-PCC were observed. Both okadaic acid and calyculin A are specific inhibitors of type 1 and type 2A protein serine/threonine phosphatases, suggesting that these phosphatases play