LAUSR

The primary cilium is elongated from the mother centriole and has diverse signaling roles during development and disease. The CP110-CEP97 complex functions as a negative regulator of ciliogenesis, although the mechanisms regulating its mother centriole localization are poorly understood. Here we show that M-Phase Phosphoprotein 9 (MPP9) is recruited by Kinesin Family Member 24 (KIF24) to the distal end of mother centriole where it forms a ring-like structure and recruits CP110-CEP97 by directly binding CEP97. Loss of MPP9 causes abnormal primary cilia formation in growing cells and mouse kidneys. After phosphorylation by Tau Tubulin Kinase 2 (TTBK2) at the beginning of ciliogenesis, MPP9 is targeted for degradation via the ubiquitin-proteasome system, which facilitates the removal of CP110 and CEP97 from the distal end of the mother centriole. Thus, MPP9 acts as a regulator of ciliogenesis by regulating the localization of CP110-CEP97 at the mother centriole.Ciliogenesis is negatively regulated by the CP110-CEP97 complex, although the mechanism controlling mother centriole localization is poorly understood. Here, Huang et al. show that KIF24 recruits MMP9 to the mother centriole, where it regulates ciliogenesis by controlling CP110-CEP97 recruitment.