Identification and characterization of the novel centrosomal protein centlein.
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.
Makino
Koji
K
Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
Umeda
Kazuaki
K
Uezu
Akiyoshi
A
Hiragami
Yukari
Y
Sakamoto
Tatsuhiko
T
Ihn
Hironobu
H
Nakanishi
Hiroyuki
H
D000818:Animals; D016466:CHO Cells; D019556:COS Cells; D018797:Cell Cycle Proteins / Q000378:metabolism*; D018385:Centrosome / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008938:Mitosis; D008970:Molecular Weight; D041681:NIH 3T3 Cells; D021381:Protein Transport; D051381:Rats
D018797:Cell Cycle Proteins; C526121:Cntln protein, rat