Cleavage of TFIIA by Taspase1 Activates TRF2-Specified Mammalian Male Germ Cell Programs

•Taspase1 cleaves TFIIA is key to mammalian male germ cell transcription programs•TFIIA noncleavage (nc) results in sperm compaction defects due to low TNPs and PRMs•Cleaved TFIIA complexes with TRF2 to form testis-specific transcription machinery•Taspase1−/− and TFIIA nc/nc mice exhibit same testicular defects as TRF2−/− mice

SummaryThe evolution of tissue-specific general transcription factors (GTFs), such as testis-specific TBP-related factor 2 (TRF2), enables the spatiotemporal expression of highly specialized genetic programs. Taspase1 is a protease that cleaves nuclear factors MLL1, MLL2, TFIIAα-β, and ALFα-β (TFIIAτ). Here, we demonstrate that Taspase1-mediated processing of TFIIAα-β drives mammalian spermatogenesis. Both Taspase1−/− and noncleavable TFIIAα-βnc/nc testes release immature germ cells with impaired transcription of Transition proteins (Tnp) and Protamines (Prm), exhibiting chromatin compaction defects and recapitulating those observed with TRF2−/− testes. Although the unprocessed TFIIA still complexes with TRF2, this complex is impaired in targeting and thus activating Tnp1 and Prm1 promoters. The current study presents a paradigm in which a protease (Taspase1) cleaves a ubiquitously expressed GTF (TFIIA) to enable tissue-specific (testis) transcription, meeting the demand for sophisticated regulation of distinct subsets of genes in higher organisms.

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