title: Identification of BCAP, a new protein associated with basal bodies and centrioles.
abstract: Cilia exert critical functions in numerous organisms, including that of cell motility, fluid transport and protozoan locomotion. Defects in this organelle can lead to lethal pathologies in humans, including primary ciliary dyskinesia. An understanding of the cilia formation process would lead to better characterization of defects involved in such pathologies. In the present study, we identified a gene encoding a novel human protein, BCAP for Basal body Centriole-Associated Protein, which shares homologies with a previously described protein, Outer Dense Fiber 2 (ODF2). ODF2, a major component of the sperm tail cytoskeleton, is required for the formation of mother centriole distal/subdistal appendages and the generation of primary cilia. Here, we show that the bcap gene contains 18 alternatively spliced exons and encodes five different isoforms, three long and two short ones. BCAP is preferentially expressed in cilia/flagella containing tissues. Moreover, its expression is correlated with cilia formation during mucociliary differentiation of human nasal epithelial cells. Using immunofluorescence analyses, BCAP was localized within basal bodies of ciliated cells and within centrioles of proliferating cells. In light of the several spliced isoforms of BCAP and the particular localization of the protein, BCAP isoforms could play distinct roles in cilia and in centrosomes.
authors.affiliation: Laboratoire de Cytophysiologie et Toxicologie Cellulaire, Universite Paris 7, France.
authors.forename: Cecile
authors.initials: C
authors.lastname: Ponsard
authors.forename: Virginie
authors.initials: V
authors.lastname: Seltzer
authors.forename: Eric
authors.initials: E
authors.lastname: Perret
authors.forename: Frederic
authors.initials: F
authors.lastname: Tournier
authors.forename: Sandrine
authors.initials: S
authors.lastname: Middendorp
mesh_terms: D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002502:Centrioles / Q000378:metabolism*; D018076:DNA, Complementary; D005455:Fluorescent Antibody Technique; D006801:Humans; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; C520779:ODF2L protein, human