NEDD1-dependent recruitment of the γ-tubulin ring complex to the centrosome is necessary for centriole duplication and spindle assembly

Abstract

The centrosome is the major microtubule organizing structure in somatic cells. Centrosomal microtubule nucleation depends on the protein γ-tubulin. In mammals, γ-tubulin associates with additional proteins into a large complex, the γ-tubulin ring complex (γTuRC). We characterize NEDD1, a centrosomal protein that associates with γTuRCs. We show that the majority of γTuRCs assemble even after NEDD1 depletion but require NEDD1 for centrosomal targeting. In contrast, NEDD1 can target to the centrosome in the absence of γ-tubulin. NEDD1-depleted cells show defects in centrosomal microtubule nucleation and form aberrant mitotic spindles with poorly separated poles. Similar spindle defects are obtained by overexpression of a fusion protein of GFP tagged to the carboxy-terminal half of NEDD1, which mediates binding to γTuRCs. Further, we show that depletion of NEDD1 inhibits centriole duplication, as does depletion of γ-tubulin. Our data suggest that centriole duplication requires NEDD1-dependent recruitment of γ-tubulin to the centrosome.

Quantitative analysis of human centrosome architecture by targeted proteomics and fluorescence imaging

“…GCP5 and GCP6 are also present in stoichiometric amounts, but about three times less abundant than GCP2 or GCP3, and GCP4 is nearly twice as abundant as GCP5 and GCP6, but only half as abundant as GCP2 and GCP3. Finally, three proteins associated with the γ‐TuRC, Nedd1 (Haren et al , 2006; Luders et al , 2006) and Mozart 1, and Mozart 2 (Hutchins et al , 2010; Teixido‐Travesa et al , 2010) are similarly abundant as the GCP2 and GCP3 core components of γ‐TuSC. These data extend previous biochemical studies (Murphy et al , 2001; Choi et al , 2010) and support the notion that multiple γ‐TuSCs associate with GCP4, GCP5, and GCP6 into γ‐TuRCs (Kollman et al , 2011; Lin et al , 2015).…”

γ-Tubulin-containing abnormal centrioles are induced by insufficient Plk4 in human HCT116 colorectal cancer cells

“…Alternatively, the microtubule-nucleating activity of γ-tubulin and γ-TuRC at the centriole might be restricted to assembling only microtubules of the centriolar wall. Indeed centriole and basal body formation was blocked and/or severely damaged by suppression of γ-tubulin in diverse organisms (Ruiz et al, 1999;Raynaud-Messina et al, 2004;Shang et al, 2002;Dammermann et al, 2004;Haren et al, 2006).…”

“…Several lines of evidence suggest that the fibers correspond to a disorganized form of centriolar microtubules. Plk4, a mammalian homolog of ZYG-et al, 1999;Raynaud-Messina et al, 2004;Shang et al, 2002;Dammermann et al, 2004;Haren et al, 2006). γ-Tubulin might be required for new centriole replication by stabilizing centriolar microtubules (Dammermann et al, 2008).…”

AAV-P125A-endostatin and paclitaxel treatment increases endoreduplication in endothelial cells and inhibits metastasis of breast cancer

“…Recent studies have identified a critical role of b-catenin in centriole function. 15,16 As endostatin inhibits b-catenin levels in ECs by interfering with wnt-signaling pathway, 16 we hypothesized that endostatin treatment will potentiate the cytological changes induced by paclitaxel. Therefore, we investigated the effect of paclitaxel and endostatin on endoreduplication in the ECs.…”