Protein & Cell最新文献

N4-acetylcytidine (ac4C), an emerging post-transcriptional RNA modification, plays a pivotal role in epigenetic regulation. Ac4C is detected not only in tRNA, rRNA and mRNA, but also in miRNA, lncRNA, viral RNA, and even DNA. Functionally, ac4C stabilizes mRNA, enhances protein translation fidelity, and impacts various biological processes and diseases such as cancer, inflammation, immune regulation, neural diseases, osteogenic differentiation, cardiovascular diseases, viral infections, and replication. Current research primarily focuses on ac4C's roles in cancer progression and immunity, with emerging findings in gynecological diseases and reproduction. However, a comprehensive understanding of ac4C's implications in reproductive health is lacking. This review provides a historical perspective on ac4C's discovery and detection methods, elucidates its functions in reproductive development and gynecological disorders, and offers insights for further research in reproductive health. This review aims to pave the way for innovative therapeutic approaches and precise diagnostic tools tailored to this field.

Nipah virus (NiV) and related viruses form a distinct henipavirus genus within the Paramyxoviridae family. NiV continues to spillover into the humans causing deadly outbreaks with increasing human-bat interaction. NiV encodes the large protein (L) and phosphoprotein (P) to form the viral RNA polymerase machinery. Their sequences show limited homologies to those of non-henipavirus paramyxoviruses. We report two cryo-electron microscopy (cryo-EM) structures of the Nipah virus (NiV) polymerase L-P complex, expressed and purified in either its full-length or truncated form. The structures resolve the RNA-dependent RNA polymerase (RdRp) and polyribonucleotidyl transferase (PRNTase) domains of the L protein, as well as a tetrameric P protein bundle bound to the L-RdRp. L-protein C-terminal regions are unresolved, indicating flexibility. Two PRNTase domain zinc-binding sites, conserved in most Mononegavirales, are confirmed essential for NiV polymerase activity. The structures further reveal anchoring of the P protein bundle and P protein X domain (XD) linkers on L, via an interaction pattern distinct among Paramyxoviridae. These interactions facilitate binding of a P protein XD linker in the nucleotide entry channel and distinct positioning of other XD linkers. We show that the disruption of the L-P interactions reduces NiV polymerase activity. The reported structures should facilitate rational antiviral-drug discovery and provide a guide for the functional study of NiV polymerase.

Successful cloning through somatic cell nuclear transfer (SCNT) faces significant challenges due to epigenetic obstacles. Recent studies have highlighted the roles of H3K4me3 and H3K27me3 as potential contributors to these obstacles. However, the underlying mechanisms remain largely unclear. In this study, we generated genome-wide maps of H3K4me3 and H3K27me3 in mouse pre-implantation NT embryos. Our analysis revealed aberrantly over-represented broad H3K4me3 domain and H3K27me3 signal lead to increased bivalent marks at gene promoters in NT embryos compared with naturally fertilized (NF) embryos at the 2-cell stage, which may link to relatively low levels of H3K36me3 in NT 2-cell embryos. Notably, the overexpression of Setd2, a H3K36me3 methyltransferase, successfully restored multiple epigenetic marks, including H3K36me3, H3K4me3 and H3K27me3. Additionally, it reinstated the expression levels of ZGA-related genes by re-establishing H3K36me3 at gene body regions, which excluded H3K27me3 from bivalent promoters, ultimately improving cloning efficiency. These findings highlight the excessive bivalent state at gene promoters as a potent barrier and emphasize the removal of these barriers as a promising approach for achieving higher cloning efficiency.