ODF2 negatively regulates CP110 levels at centrioles/basal bodies to control biogenesis of primary cilia

Abstract

Primary cilia are essential sensory organelles that develop when an inhibitory cap consisting of CP110 and other proteins is eliminated. Degradation of CP110 by the ubiquitin-dependent proteasome pathway mediated by NEURL4 and HYLS1 removes the inhibitory cap. Here, we investigated the suitability of rapamycin-mediated dimerization for centriolar recruitment and asked whether the induced recruitment of NEURL4 or HYLS1 to the centriole promotes primary cilia development and CP110 degradation. We used rapamycin-mediated dimerization with ODF2 to induce their targeted recruitment to the centriole. We found decreased CP110 levels in transfected cells, but independent of rapamycin-mediated dimerization. By knocking down ODF2, we show that ODF2 controls CP110 levels. Overexpression of ODF2 is not sufficient to promote the formation of primary cilia, but overexpression of NEURL4 or HYLS1 is. Co-expression of ODF2 and HYLS1 resulted in the formation of tube-like structures, indicating an interaction. Thus, ODF2 controls primary cilia formation by negatively regulating the concentration of CP110 levels. Our data suggest that ODF2 most likely acts as a scaffold for the binding of proteins such as NEURL4 or HYLS1 to mediate CP110 degradation. SummaryNEURL4 and HYLS1 mediate the degradation of CP110 to allow cilium formation. We used rapamycin-mediated dimerization with ODF2 to recruit NEURL4 and HYLS1 to the centriole and show that ODF2 controls CP110 levels.