Project description:The outbreak-causing monkeypox virus of 2022 (2022 MPXV) is classified as a clade IIb strain and phylogenetically distinct from prior endemic MPXV strains (clades I or IIa), suggesting that its virological properties may also differ. Here, we used human keratinocytes and induced pluripotent stem cell-derived colon organoids to examine the efficiency of viral growth in these cells and the MPXV infection-mediated host responses. MPXV replication was much more productive in keratinocytes than in colon organoids. We observed that MPXV infections, regardless of strain, caused cellular dysfunction and mitochondrial damage in keratinocytes. Notably, a significant increase in the expression of hypoxia-related genes was observed specifically in 2022 MPXV-infected keratinocytes. Our comparison of virological features between 2022 MPXV and prior endemic MPXV strains revealed signaling pathways potentially involved with the cellular damages caused by MPXV infections and highlights host vulnerabilities that could be utilized as protective therapeutic strategies against human mpox in the future.
Project description:Recognition of post-translational modifications on histones by epigenetic readers is a fundamental mechanism for the regulation of chromatin and transcription. Compared to the large number of readers that recognize histone methylation, only a few acetyllysine readers have been identified, including bromodomain, YEATS, and double plant homeodomain zinc finger (DPF). Here, we report the identification of a novel reader of histone H3, the ZZ-type zinc finger (ZZ) domain of ZZZ3, a subunit of the Ada-Two-A Containing (ATAC) histone acetyltransferase complex. The solution NMR structure of the ZZ in complex with the H3 peptide reveals a unique histone-binding mechanism involving caging of the N-terminal Alanine 1 of histone H3 in an acidic cavity of the ZZ domain. Importantly, acetylation on Lysine 4 of H3 (H3K4ac) enhances the binding, and in cells, ZZZ3 colocalizes with H3K4ac across the genome. The recognition of histone acetylation by ZZ is essential for chromatin occupancy of ZZZ3 and functions of the ATAC complex. Depletion of ZZZ3 or disruption of the ZZ-H3 interaction dampens ATAC dependent promoter histone H3K9 acetylation and the expression of ribosomal protein encoding genes. Overall, our study identifies the ZZ domain of ZZZ3 as a novel epigenetic reader that links the GCN5/ATAC complex to histone acetylation.
