title: The two human centrin homologues have similar but distinct functions at Tetrahymena basal bodies.
abstract: Centrins are a ubiquitous family of small Ca(2+)-binding proteins found at basal bodies that are placed into two groups based on sequence similarity to the human centrins 2 and 3. Analyses of basal body composition in different species suggest that they contain a centrin isoform from each group. We used the ciliate protist Tetrahymena thermophila to gain a better understanding of the functions of the two centrin groups and to determine their potential redundancy. We have previously shown that the Tetrahymena centrin 1 (Cen1), a human centrin 2 homologue, is required for proper basal body function. In this paper, we show that the Tetrahymena centrin 2 (Cen2), a human centrin 3 homologue, has functions similar to Cen1 in basal body orientation, maintenance, and separation. The two are, however, not redundant. A further examination of human centrin 3 homologues shows that they function in a manner distinct from human centrin 2 homologues. Our data suggest that basal bodies require a centrin from both groups in order to function correctly.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Colorado-Boulder, Boulder, CO 80309, USA.
authors.forename: Tyson
authors.initials: T
authors.lastname: Vonderfecht
authors.forename: Michael W
authors.initials: MW
authors.lastname: Cookson
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Giddings
authors.forename: Christina
authors.initials: C
authors.lastname: Clarissa
authors.forename: Mark
authors.initials: M
authors.lastname: Winey
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D002502:Centrioles / Q000378:metabolism* / Q000648:ultrastructure; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D020033:Protein Isoforms / Q000145:classification / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D016808:Tetrahymena thermophila / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: C472752:CETN2 protein, human; C107745:CETN3 protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D020033:Protein Isoforms; D015800:Protozoan Proteins; D049452:Green Fluorescent Proteins