Centromere Protein Nudel An Important Role In Centrosome And Gb

Centrosome is the major microtubule (MT)-organizing center in animal cells. Although the cytoplasmic dynein regulator Nudel binds centrosomes, its roles herein remain unclear. Here we show that Nudel is a mother centriole protein with rapid turnover (t1/2≈2.1 min) independent of MTs in Cos7 cells. Moreover, it targets to the second mother centriole in late S or G2 phase during centrosome duplication, with a timing later than ninein but earlier than dynactin. The region containing residues 256-291 is essential for centrosomal localization. Nudel complexes with a subset of centrosomal proteins including dynactin, PCM-1, pericentrin, and γ-tubulin, but not centrin-2. A dynein-binding-defective mutant dislocates centrosomal dynactin and PCM-1 with little effects on pericentrin and γ-tubulin in Cos7. Silencing Nudel expression in HeLa cells inhibits MT nucleation and anchoring at the centrosome and markedly decreases centrosomal targeting of the associated proteins. Centrosome duplication is also delayed. Our results suggest Nudel as an integral centrosomal component involved in both dynein-dependent and independent centrosome assembly.