Inactivation of the Catalytic Activity of Mps1 Kinase Prevents Its Own Degradation at Centrosomes.

Mps1 kinase plays important roles in regulating centriole assembly, apart from its essential role in spindle assembly checkpoint. Here we report a novel mode of regulating centrosomal Mps1 level, which is governed by its own catalytic activity that promotes its degradation at centrosomes. A kinase-dead mutant of Mps1 or catalytically inactive Mps1 due to treatment with a specific kinase inhibitor is protected from degradation at centrosomes. This autoregulatory mode of controlling Mps1 activity at centrosomes likely restricts excess centriole production in a dividing cell.