The microtubule nucleation activity of centrobin in both the centrosome and cytoplasm

Abstract

Centrobin resides in daughter centriole and play a critical role in centriole duplication. Nucleation and stabilization of microtubules are known biological activities of centrobin. Here, we report a specific localization of centrobin outside the centrosome. Centrobin was associated with the stable microtubules. In hippocampal cells, centrobin formed cytoplasmic dots in addition to the localization at both centrosomes with the mother and daughter centrioles. Such specific localization pattern suggests that cytoplasmic centrobin is not just a reserved pool for centrosomal localization but also has a specific role in the cytoplasm. In fact, centrobin enhanced microtubule formation outside as well as inside the centrosome. These results propose specific roles of the cytoplasmic centrobin for noncentrosomal microtubule formation in specific cell types and during the cell cycle.

Centrobin controls primary ciliogenesis in vertebrates

“…We observed this association with both the endogenous centrobin protein and with GFP-tagged, overexpressed centrobin. Although centrobin has mainly been observed at daughter centrioles, it localized to both centrioles in cultured mouse hippocampal neurons ( Jeong et al, 2007 ; Gudi et al, 2011 ; Shin et al, 2015 ). Strikingly, we found that centrobin-deficient cells had a marked defect in forming primary cilia, which could be rescued by reexpression of centrobin ( Fig.…”

“…It remains to be determined whether centrosome localization of centrobin is required for ciliogenesis. Appropriate regulation of microtubule stability is an obvious candidate mechanism by which centrobin may contribute to ciliogenesis ( Jeong et al, 2007 ; Gudi et al, 2011 ; Shin et al, 2015 ).…”

Formation and function of the manchette and flagellum during spermatogenesis

“…Centrobin, which is required for microtubule nucleation and stabilization (Gudi et al 2011), has been localized to the acroplaxome, marginal ring, manchette and centrosome during spermatogenesis (Liska et al 2009). A recent study demonstrated a specific localization for centrobin in the cytoplasm outside of the centrosome, which suggest a possible role as a microtubule nucleation site outside of the centrosome (Shin et al 2015). Centrobin C-terminal truncation results in decapitated sperm with head and tail malformations.…”

The DNA replication protein Cdc6 inhibits the microtubule-organizing activity of the centrosome

“…Cdc6-depleted cells were incubated on ice for 1 h to depolymerize microtubules, followed by incubation at 37°C to allow microtubule regrowth (38). Microtubule regrowth from the centrosomes was measured for 15 s by immunostaining cells with either anti-␣-tubulin or anti-EB1 antibodies to detect microtubule formation (Fig.…”