title: A novel testis protein, RSB-66, interacting with INCA1 (inhibitor of Cdk interacting with cyclin A1).
abstract: rsb-66 is a novel gene from a suppression subtracted hybridization (SSH) library of round spermatid-specific cDNAs against those of primary spermatocytes. It was found to be specifically expressed in round spermatids. To explore the function of RSB-66, a yeast two-hybrid system was used to screen for potential interacting partners in a human testis cDNA library. HSD45, also known as INCA1 (inhibitor of Cdk interacting with cyclin A1), was identified as one of the positive clones. The interaction between RSB-66 and INCA1 was demonstrated to occur by GST pull down and coimmunoprecipitation. Using immunofluorescence, RSB-66 was found to be specifically expressed in round spermatids, mainly in the cytoplasm. When being transfected into HeLa cells, RSB-66 and INCA1 were found to be co-localized principally in the cytoplasm. The alpha helix in the RSB-66 C terminal and two amino acid residues (tyr117 and his119) appear to be crucial for its function.
authors.affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, Beijing, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.forename: Tinghui
authors.initials: T
authors.lastname: Hu
authors.forename: Gang
authors.initials: G
authors.lastname: Liang
authors.forename: Maojun
authors.initials: M
authors.lastname: Yang
authors.forename: Shudong
authors.initials: S
authors.lastname: Zong
authors.forename: Shiying
authors.initials: S
authors.lastname: Miao
authors.forename: Samuel S
authors.initials: SS
authors.lastname: Koide
authors.forename: Linfang
authors.initials: L
authors.lastname: Wang