Polo-like kinases: a team that plays throughout mitosis

Abstract

When the first mutant allele of the Drosophila gene polo was first characterized over 10 years ago, attention focused on the defects that centrosome behavior exhibited at various stages of development (Sunkel and Glover 1988). The subsequent realization that the serine-threonine kinase it encodes is highly conserved from yeasts to humans has provoked a flurry of investigation into the function of the enzyme. A role for the polo-like kinases (plks) in regulating centrosome behavior has been borne out in several organisms, and the enzymes have attracted further attention recently with the realization that they regulate multiple stages of mitotic progression. In this article we review the current status of our understanding of the functions of plks from the time of commitment to M phase in the activation of Cdc25, through the activation of the anaphase promoting complex (APC), to the regulation of late mitotic events essential for cytokinesis. We discuss how to reconcile the sometimes apparently disparate observations made upon plk function in different organisms.

Aurora2/BTAK/STK15 is involved in cell cycle checkpoint and cell survival of aggressive non‐Hodgkin's lymphoma

“…Here, using antisense modulation of the Aurora2/BTAK/ STK15 transcript, we have shown that transient and permanent downmodulation of the Aurora2/BTAK/STK15 gene in NHL cell lines significantly reduced the rate of cell proliferation, and that stable antisense transfectants exhibited G0/G1-phase cell cycle accumulation. These results indicate that Aurora2/BTAK/STK15-associated cell cycle change may act as one possible cause of tumorgenesis in aggressive NHLs (Zhou et al, 1998), and that the tight regulation of cell cycle change by phosphorylation and degradation events reported recently (Glover et al, 1998;Giet & Prigent, 1999;Walter et al, 2000) is likely to be critical. On the other hand, stable transfection using the Aurora2/BTAK/STK15 gene did not show any biological changes in our experiments, suggesting that these NHL cell lines already express a useful amount of Aurora2/BTAK/ STK15 and that this amount is sufficient for malignant transformation to occur.…”

Protein kinases in control of the centrosome cycle

“…a Yeast Plks (Cdc5p, Plo1p) have also been localized to the SPB [13]. b A second subclass of aurora-related kinases appears to have no function at the centrosome and instead is required for cytokinesis.…”

RNAi-mediated gene silencing in tumour tissue using replication-competent retroviral vectors

“…PLK1 is an important regulator of many cell cycle related events and its depletion induces G2 arrest and apoptosis. [26][27][28] To investigate the effect of PLK1 depletion on the cell cycle we analysed infected cells by flow cytometry. Cells infected with aMLV-shPLK1-1 were trapped in G2-phase at day 3 post infection.…”