CAMSAP3 accumulates in the pericentrosomal area and accompanies microtubules release from the centrosome via katanin

Abstract

The epithelium has apico-basal axis polarity that plays an important role in absorption, excretion and other physiological functions. In epithelial cells, a substantial number of noncentrosomal microtubules (MTs) are scattered in the cytoplasm with an apico-basal polarity to adapt to these complex functions. Several previous studies have found that noncentrosomal MTs are nucleated at the centrosome, and then released and translocated elsewhere. However, the detailed process and molecular mechanism remains largely unknown. In this study, we found that Nezha, also called CAMSAP3 (calmodulin-regulated spectrin-associated protein3), a noncentrosomal MT minus-end protein, accumulated in the pericentrosomal area and accompanied the release of MTs from the centrosome; whereas depletion of CAMSAP3 prevented MT release and instead caused focusing of MTs at centrosomes. Further studies demonstrated CAMSAP3 precisely coordinated with dynein and katanin to regulate the MT detachment process. In conclusion, our results indicate CAMSAP3 is a key molecule for generation of noncentrosomal MT.