A central question in the study of cell proliferation is, what controls cell-cycle transitions? Although the accumulation of mitotic cyclins drives the transition from the G2 phase to the M phase in embryonic cells, the trigger for mitotic entry in somatic cells remains unknown. We report that the synergistic action of Bora and the kinase Aurora A (Aur-A) controls the G2-M transition. Bora accumulates in the G2 phase and promotes Aur-A-mediated activation of Polo-like kinase 1 (Plk1), leading to the activation of cyclin-dependent kinase 1 and mitotic entry. Mechanistically, Bora interacts with Plk1 and controls the accessibility of its activation loop for phosphorylation and activation by Aur-A. Thus, Bora and Aur-A control mitotic entry, which provides a mechanism for one of the most important yet ill-defined events in the cell cycle.
PubMed ID: 18566290
PMC ID: PMC2834883
Article link: Science.
Grant support: GM062852 NIGMS NIH HHS , HL079442 NHLBI NIH HHS , RR11823-10 NCRR NIH HHS , P41 RR011823-10 NCRR NIH HHS , R01 GM062852-05 NIGMS NIH HHS , R01 HL079442-04 NHLBI NIH HHS , P41 RR011823 NCRR NIH HHS , R01 HL079442 NHLBI NIH HHS
Genes referenced: aurka bora plk1