Function and regulation of the novel tubulin-associated protein RITA in mitosis

RITA (RBP-J interacting and tubulin associated) is a newly identified protein which acts as a negative modulator of the Notch-signaling pathway. RITA possesses a tubulin-interaction domain, a functional nuclear localization signal (NLS) and a nuclear export signal (NES). Interestingly, RITA binds to tubulin in the cytoplasm and it is to be found at the centrosomes and the mitotic spindle during mitosis. We are interested in the role and regulation of RITA in the cell cycle, in particular, in mitosis. We show that RITA is specifically phosphorylated by two important mitotic kinases cyclin-dependent kinase 1 (Cdk1…