Makino Koji, Umeda Kazuaki, Uezu Akiyoshi, Hiragami Yukari, Sakamoto Tatsuhiko, Ihn Hironobu, Nakanishi Hiroyuki
Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
Biochem Biophys Res Commun. 2008 Feb 22;366(4):958-62. doi: 10.1016/j.bbrc.2007.12.050. Epub 2007 Dec 18.
Centrosomes function as the major microtubule (MT)-organizing center. They are composed of a pair of centrioles which are surrounded by the pericentriolar material. Here, we describe the molecular characterization of a novel protein, named centlein (centrosomal protein). Centlein was a protein of 721 amino acids with a calculated molecular weight of 82,717 and possessed coiled-coil domains. Western blot analysis indicated that centlein was ubiquitously expressed. Endogenous centlein as well as enhanced green fluorescent protein-fused centlein was localized at centrosomes in interphase and mitosis. When centrosomes were isolated from cells treated with nocodazole, an MT-disrupting agent, centlein and the centrosomal protein, gamma-tubulin, were enriched in the same fractions. These data indicate that centlein is a widespread centrosomal protein and that its association with centrosomes is independent of MTs. Centlein appeared to be enriched in the mother centriole in G1 phase, suggesting possible involvement of centlein in mother-centriole-related functions, such as duplication of centrioles and generation of primary cilia.
中心体作为主要的微管（MT）组织中心发挥作用。它们由一对中心粒组成，中心粒被中心粒周围物质所包围。在此，我们描述了一种名为centlein（中心体蛋白）的新型蛋白质的分子特征。Centlein是一种含有721个氨基酸的蛋白质，计算分子量为82,717，具有卷曲螺旋结构域。蛋白质免疫印迹分析表明centlein在各处均有表达。内源性centlein以及增强型绿色荧光蛋白融合的centlein在间期和有丝分裂期均定位于中心体。当从用诺考达唑（一种破坏微管的药物）处理的细胞中分离出中心体时，centlein和中心体蛋白γ-微管蛋白富集于相同的组分中。这些数据表明centlein是一种广泛存在的中心体蛋白，并且其与中心体的结合不依赖于微管。Centlein似乎在G1期富集于母中心粒，这表明centlein可能参与与母中心粒相关的功能，如中心粒的复制和初级纤毛的产生。
