The eukaryotic genome is organized in the form of a highly compact nucleoprotein complex, the chromatin. Nucleosome, the basic unit of chromatin, consists of ~147 bp of DNA wrapped 1.65 times around a histone octamer composed of the core histones H2A, H2B, H3, and H4, in two copies each. Within the chromatin, the distance between two consecutive nucleosome cores varies between 20-100 bp of linker DNA that associates with a special class of histones known as the linker histones (H1 and H5).
Several nucleosomes get organized on chromosomal DNA in a linear ‘beads on a string’ pattern connected by the linker DNA that constitutes a nucleosomal array, forming the lowest functional unit of chromatin compaction and is permissive to transcription. Further organization in the form of 30 nm chromatin fiber is thought to be repressive to transcription events. Another level of compaction is brought about through the histone tail-mediated interaction of 30 nm chromatin fibers. The formation of chromatin thus aids hierarchical compaction and compartmentation.
Despite the high degree of compaction, DNA should still be readily accessible to allow interaction with several different protein factors regulating its functions such as replication, transcription, repair, and recombination. The continuous interaction of chromatin with a myriad of proteins, including epigenetic factors, chromatin remodelers, and histone chaperones which act either in an ATP-dependent or ATP independent manner, is vital to maintaining its dynamic nature. The dynamic nature of chromatin thus influences almost all genome functions. Recent years have witnessed rapid progress in the structure and function of chromatin; however, these studies were mainly focused on a few biological processes.
This Research Topic aims to gather studies that elucidate molecular mechanisms by which genetic and epigenetic factors bring about changes in the structure and function of chromatin and thereby affect the biological process such as gene expression, DNA replication, DNA damage, etc. Together with biochemical, genetic, cell biology analyses, and omics studies, we hope to better understand how histones, histone variants, and chromatin remodeling factors are involved in regulating chromatin structure and function. With this, the field will gain insights into how changes in chromatin structure affect its function in both normal and diseased states.
This Research Topic invites Original Research, Methods, Review, Mini-review, Opinion, Hypothesis & Theory articles around the broad theme of Chromatin Structure and Function covering the following aspects, but not limited to:
1) Chromatin structure, dynamics, and remodeling
2) Chromatin assembly, replication, and repair
3) Histone posttranslational modifications
4) Epigenetic regulation of chromatin
5) DNA methylation
6) Linker histones
The eukaryotic genome is organized in the form of a highly compact nucleoprotein complex, the chromatin. Nucleosome, the basic unit of chromatin, consists of ~147 bp of DNA wrapped 1.65 times around a histone octamer composed of the core histones H2A, H2B, H3, and H4, in two copies each. Within the chromatin, the distance between two consecutive nucleosome cores varies between 20-100 bp of linker DNA that associates with a special class of histones known as the linker histones (H1 and H5).
Several nucleosomes get organized on chromosomal DNA in a linear ‘beads on a string’ pattern connected by the linker DNA that constitutes a nucleosomal array, forming the lowest functional unit of chromatin compaction and is permissive to transcription. Further organization in the form of 30 nm chromatin fiber is thought to be repressive to transcription events. Another level of compaction is brought about through the histone tail-mediated interaction of 30 nm chromatin fibers. The formation of chromatin thus aids hierarchical compaction and compartmentation.
Despite the high degree of compaction, DNA should still be readily accessible to allow interaction with several different protein factors regulating its functions such as replication, transcription, repair, and recombination. The continuous interaction of chromatin with a myriad of proteins, including epigenetic factors, chromatin remodelers, and histone chaperones which act either in an ATP-dependent or ATP independent manner, is vital to maintaining its dynamic nature. The dynamic nature of chromatin thus influences almost all genome functions. Recent years have witnessed rapid progress in the structure and function of chromatin; however, these studies were mainly focused on a few biological processes.
This Research Topic aims to gather studies that elucidate molecular mechanisms by which genetic and epigenetic factors bring about changes in the structure and function of chromatin and thereby affect the biological process such as gene expression, DNA replication, DNA damage, etc. Together with biochemical, genetic, cell biology analyses, and omics studies, we hope to better understand how histones, histone variants, and chromatin remodeling factors are involved in regulating chromatin structure and function. With this, the field will gain insights into how changes in chromatin structure affect its function in both normal and diseased states.
This Research Topic invites Original Research, Methods, Review, Mini-review, Opinion, Hypothesis & Theory articles around the broad theme of Chromatin Structure and Function covering the following aspects, but not limited to:
1) Chromatin structure, dynamics, and remodeling
2) Chromatin assembly, replication, and repair
3) Histone posttranslational modifications
4) Epigenetic regulation of chromatin
5) DNA methylation
6) Linker histones
