TSPY1 suppresses USP7-mediated p53 function and promotes spermatogonial proliferation

Area of Science:

• Reproductive Biology
• Molecular Cell Biology
• Biochemistry

Background:

• Testis-specific protein Y-linked 1 (TSPY1) is crucial for spermatogenesis, but its precise function remains unclear.
• Understanding TSPY1's regulatory mechanisms is vital for germline homeostasis and male fertility.

Purpose of the Study:

• To elucidate the molecular mechanism by which TSPY1 regulates spermatogonial proliferation.
• To investigate the interaction of TSPY1 with key cellular proteins involved in cell cycle control and apoptosis.

Main Methods:

• Co-immunoprecipitation assays to identify interacting partners.
• Western blotting to assess protein levels and ubiquitylation.
• Quantitative real-time PCR to measure gene expression.
• Cell proliferation assays and apoptosis detection.
• In vitro studies using Tspy1-deficient mouse spermatogonia.

Main Results:

• TSPY1 interacts with TSPY-like 5 (TSPYL5) and enhances its binding to USP7 and p53.
• TSPY1 promotes p53 ubiquitylation and degradation by inducing USP7 ubiquitination and subsequent degradation.
• TSPY1-mediated p53 degradation accelerates G2/M phase transition and decreases apoptosis, promoting cell proliferation.
• TSPY1 enhances spermatogonial proliferation in mice by reducing Usp7-modulated p53 levels.

Conclusions:

• TSPY1 acts as a suppressor of USP7-mediated p53 function, thereby promoting p53-dependent cell proliferation.
• TSPY1 plays a significant role in maintaining germline homeostasis by regulating spermatogonial p53 function.
• TSPY1 holds potential for regulating human spermatogonial proliferation through the USP7-p53 signaling pathway.