Involvement of a centrosomal protein kendrin in the maintenance of centrosome cohesion by modulating Nek2A kinase...

Centrosome cycle is strictly coordinated with chromosome duplication cycle to ensure the faithful segregation of chromosomes. Centrosome duplication occurs from the beginning of S phase, and the duplicated centrosomes are held together by centrosome cohesion to function as a single microtubule organizing center during interphase. At late G2 phase centrosome cohesion is disassembled by Nek2A kinase-mediated phosphorylation and, as a consequence, centrosomes are split and constitute spindle poles in mitosis. It has been reported that depletion of a centrosomal protein kendrin (also named pericentrin) induces premature centrosome splitting in interphase, however, it remains unknown how kendrin contributes to the maintenance of centrosome cohesion. Here we show that kendrin associates with Nek2A kinase, which exhibits considerably low activity. Nek2A kinase activity is inhibited in vitro by addition of the Nek2A-binding region of kendrin in a dose-dependent manner. Furthermore, ectopic expression of the same region decreases the number of the cells with split centrosomes at late G2 phase. Taken together, these results suggest that kendrin anchors Nek2A and suppresses its kinase activity at the centrosomes, and thus, is involved in the mechanism to prevent premature centrosome splitting during interphase.