HSF2BP represses BNC1 transcriptional activity by sequestering BNC1 to the cytoplasm

• We identified HSF2BP as a binding partner of BNC1.
• HSF2BP represses BNC1 transcriptional activity.
• HSF2BP translocates BNC1 from the nucleus to the cytoplasm.

Basonuclin (BNC1), a zinc finger transcriptional factor, is essential for mouse spermatogenesis. However, the regulatory mechanisms of BNC1 in spermatogenesis are poorly understood. In this study, we identified HSF2BP, a testis-specific binding protein of HSF2, as a binding partner of BNC1 by using yeast two-hybrid screening. HSF2BP could interact with and inhibit BNC1 transcriptional activity without affecting its expression level. Moreover, coexpression of HSF2BP with BNC1 resulted in a striking redistribution of BNC1 to the cytoplasm. These data suggest that HSF2BP may play a pivotal role in regulating BNC1 transcriptional activity and subcellular localization during spermatogenesis.

Structured summary of protein interactionsBnc1physically interacts with HSF2BP by two hybrid (View interaction)Bnc1 and HSF2BPcolocalize by fluorescence microscopy (View interaction)Bnc1physically interacts with HSF2BP by anti tag coimmunoprecipitation (View Interaction: 1, 2)