GSE139072
Nuclear Poly(A)-binding Protein 1-like (PABPN1L) Mediates Cytoplasmic mRNA Decay As a Placeholder during Maternal-to-zygotic Transition
Maternal mRNA degradation is a critical event of maternal-to-zygotic transition (MZT) that determines the developmental potential of early embryos. Nuclear Poly(A)-binding proteins (PABPNs) are extensively involved in mRNA post-transcriptional regulations, but their functions in mammalian MZT has not been investigated. In this study, we identified a novel maternal-effect factor PABPN1-like (PABPN1L), rather than its ubiquitously expressed homolog PABPN1, as an RNA-binding adapter of the mammalian MZT licensing factor BTG4 which mediates maternal mRNAs clearance. Female Pabpn1l null mice produced morphologically normal oocytes but were infertile owing to early developmental arrest of the resultant embryos at the 1-to-2-cell stages without undergoing ZGA. Deletion of Pabpn1l impairs the deadenylation and degradation of a subset of BTG4-targeted maternal mRNAs during MZT. In addition to recruiting BTG4 to the mRNA 3'-poly(A) tails, PABPN1L is also required for BTG4 protein accumulation in maturing oocytes by protecting BTG4 from SCF-ßTrCP1 E3 ubiquitin ligase-mediated polyubiquitination and degradation. This study highlights a noncanonical cytoplasmic function of nuclear poly(A)-binding proteins mRNA turnover as well as its physiological importance during MZT. Overall design: GV oocytes, zygotes and 2-cell embryos of WT and Pabpn1l knockout for duplicates are performed RNA sequencing.