Expression Of Protein Tyrosine Phosphatase Ptp-Rl10 And Its Isoform In The Mouse Testis

Background: The cytoplasmic-type protein tyrosine phosphatase PTP-RL10/PTPD1/PTP2E contains an ezrin-like domain and associates with the c-Src protein tyrosine kinase. Because tyrosine phosphorylation regulated by protein tyrosine kinases and phosphatases is involved in activation, migration, differentiation and proliferation of various cell types, the expression of PTP-RL10 and c-src in the mouse testis was investigated.Methods: Testes of wild-type mice and W/W-v mutant mice that lack germ cells were analyzed by northern blotting, in situ hybridization histochemistry and reverse transcriptase-polymerase chain reaction for the expression of PTP-RL10, its isoform PTP-RL10b and c-src. Expression in the Sertoli cell lines, TM4 and TAMA26 was also analyzed.Results: PTP-RL10 transcripts of 5.7 kb and 2.9 kb in size were detected in the testis. In Situ hybridization histochemistry demonstrated that the 5.7 kb transcripts were expressed in pachytene spermatocytes and somatic cells including Sertoli cells, in which c-src transcripts were detected. The 2.9 kb transcript encoded a novel isoform, PTP-RL10b, that has the catalytic domain but not the domains that associate with c-Src. PTP-RL10b was expressed mainly in the testicular somatic cells. TM4 and TAMA26 cells were found to co-express PTP-RL10, PTP-RL10b and c-src transcripts.Conclusion: PTP-RL10 and its isoform are expressed in the Sertoli cells and are suggested to play roles in spermatogenesis by interacting with c-Src and/or other protein(s).