Figure 1

Plk1 colocalizes with PBIP1 at the interphase and mitotic centromeres. (A), Structure of mammalian Plk1. Numbers indicate amino acid positions. Critical amino acid residues are shown. (B-C), HeLa cells were costained with anti-Plk1 and anti-α-tubulin antibodies (B) or anti-PBIP1 and mouse anti-CREST antibodies (C). Images were collected with a Zeiss LSM510 confocal microscope. Arrows, centrosome-localized Plk1 signals. (D), Model illustrating the Plk1-PBIP1 interaction at the centromeres. PBIP1 functions as a centromeric scaffold to recruit Plk1. Once localized at the centromeres, Plk1 phosphorylates either PBIP1 or other centromeric Plk1 substrates. KD, kinase domain; PBD, polo-box domain.