TSGA10 is a Centrosomal Protein, Interacts with ODF2 and Localizes to Basal Body

TSGA10 is overexpressed in some cancers, during neural development, in embryogenesis, and in several tissues with actively dividing cells. TSGA10 protein localization to the sperm tail has been previously described. The protein is cleaved into two parts, which appear to play different functions in the sperm tail: the 27-KDa N-terminal is localized to the fibrous sheath in the principal piece, whereas its 55-KDa C-terminal of the TSGA10 forms filaments, decreases transcriptional activity of hypoxia-inducible factor (HIF)-1-alpha and accumulates in the midpiece of mature spermatozoa. Using colocalization, and coimmunoprecipitation assays, we show that TSGA10 interacts with ‘Outer Dense Fiber 2’ (ODF2), a centrosome scaffold component associated with mother centrioles. Also, our yeast two-hybrid assay shows that the full-length TSGA10 protein and its 55-KDa C-terminus portion predominantly interact with ODF2. However, the truncated N-terminus 27-KDa fibrous sheath component of TSGA10 fails to bind ODF2. Our experiments examining the localization of TSGA10, demonstrated that the full length TSGA10 protein localizes to perinuclear structures, colocalizes with γ-tubulin, and associates with the centrosome and basal body. The TSGA10 55-KDa C-terminus, but not its 27-KDa N-terminus also localizes to the centrosome and basal body. Our Real-time PCR data indicated that the levels of TSGA10 and ODF2 genes expressions correlate, in mice testes. Finally, we propose that TSGA10 is a ciliary-centrosomal protein and therefore is a good candidate for further investigation in ciliopathies, as well as, cancer biology.