A novel testis protein, RSB-66, interacting with INCA1 (inhibitor of Cdk interacting with cyclin A1).
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.
Chen
Xu
X
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, Beijing, China.
Hu
Tinghui
T
Liang
Gang
G
Yang
Maojun
M
Zong
Shudong
S
Miao
Shiying
S
Koide
Samuel S
SS
Wang
Linfang
L