Molecular requirements for PLK1 activation by T-loop phosphorylation

ABSTRACT: Activation of PLK1, a master mitotic kinase, requires phosphorylation of its activation segment on Thr210, within a basic consensus sequence for Aurora kinases. Aurora B-dependent phosphorylation of Thr210 has been reported, but other evidence identified a strict requirement for the Aurora A partner Bora for Thr210 phosphorylation. Here, we investigate the elusive mechanistic basis for this requirement. We show that Aurora A:Bora phosphorylates Thr210 of PLK1 in vitro. On the contrary, T210 was not phosphorylated by isolated Aurora A, additional Aurora A:activator complexes, or Aurora B:INCENP, even when used at high kinase/substrate ratios. A transient interaction of Bora and PLK1, identified by structural modelling and probed mutationally, is uniquely required for Thr210 phosphorylation.

SUBMITTER: Arianna Esposito-Verza 

PROVIDER: S-SCDT-10_1038-S44318-025-00681-0 | biostudies-other |

REPOSITORIES: biostudies-other