Nucleosome is the basic structural unit of the genome. During processes like DNA replication and gene transcription, the conformation of nucleosomes undergoes dynamic changes, including DNA unwrapping and rewrapping, as well as histone disassembly and assembly. However, the wrapping characteristics of nucleosomes across the entire genome, including region-specificity and their correlation with higher-order chromatin organization, remains to be studied.
View Article and Find Full Text PDFThe minichromosome maintenance complex (MCM) DNA helicase is an important replicative factor during DNA replication. The proper chromatin loading of MCM is a key step to ensure replication initiation during S phase. Because replication initiation is regulated by multiple biological cues, additional changes to MCM may provide better understanding towards this event.
View Article and Find Full Text PDFDNA replication ensures the accurate transmission of genetic information during the cell cycle. Histone variant H2A.Z is crucial for early replication origins licensing and activation in which SUV420H1 preferentially recognizes H2A.
View Article and Find Full Text PDFNat Struct Mol Biol
June 2023
The transmission and maintenance of genetic information in eukaryotic cells relies on the faithful duplication of the entire genome. In each round of division, excessive replication origins are licensed, with only a fraction activated to give rise to bi-directional replication forks in the context of chromatin. However, it remains elusive how eukaryotic replication origins are selectively activated.
View Article and Find Full Text PDFHistone H4 lysine 20 monomethylation (H4K20me1) plays a crucial role in multiple processes including DNA damage repair, DNA replication, and cell cycle control. Histone methyltransferase SET8 (previously named PR-Set7/KMT5A) mediates the chromatin deposition of H4K20me1, but how SET8 recognizes and modifies H4 in the context of the nucleosome is not fully understood. Here, we developed a simple chemical modification approach for H4K20 substitution by using the lysine analog S-ethyl-L-cysteine (Ecx).
View Article and Find Full Text PDFBackground: Metazoan cells only utilize a small subset of the potential DNA replication origins to duplicate the whole genome in each cell cycle. Origin choice is linked to cell growth, differentiation, and replication stress. Although various genetic and epigenetic signatures have been linked to the replication efficiency of origins, there is no consensus on how the selection of origins is determined.
View Article and Find Full Text PDFAn Amendment to this paper has been published and can be accessed via a link at the top of the paper.
View Article and Find Full Text PDFDNA replication is a tightly regulated process that ensures the precise duplication of the genome during the cell cycle. In eukaryotes, the licensing and activation of replication origins are regulated by both DNA sequence and chromatin features. However, the chromatin-based regulatory mechanisms remain largely uncharacterized.
View Article and Find Full Text PDFBackground: The hierarchical organization of eukaryotic chromatin plays a central role in gene regulation, by controlling the extent to which the transcription machinery can access DNA. The histone variants H3.3 and H2A.
View Article and Find Full Text PDFThe histone variants H3.3 and H2A.Z have recently emerged as two of the most important features in transcriptional regulation, the molecular mechanism of which still remains poorly understood.
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