The nucleolus is a nuclear compartment that plays an important role in ribosome biogenesis. Some structural features and epigenetic patterns are shared between nucleolar and non-nucleolar compartments. For example, the location of transcriptionally active mRNA on extended chromatin loop species is similar to that observed for transcriptionally active ribosomal DNA (rDNA) genes on so-called Christmas tree branches. Similarly, nucleolus organizer region-bearing chromosomes located a distance from the nucleolus extend chromatin fibers into the nucleolar compartment. Specific epigenetic events, such as histone acetylation and methylation and DNA methylation, also regulate transcription of both rRNA- and mRNA-encoding loci. Here, we review the epigenetic mechanisms and structural features that regulate transcription of ribosomal and mRNA genes. We focus on similarities in epigenetic and structural regulation of chromatin in nucleoli and the surrounding non-nucleolar region and discuss the role of proteins, such as heterochromatin protein 1, fibrillarin, nucleolin, and upstream binding factor, in rRNA synthesis and processing.

• MeSH
• buněčné jadérko genetika   metabolismus   ultrastruktura   MeSH
• chromatin genetika   ultrastruktura   MeSH
• epigeneze genetická * MeSH
• genetická transkripce MeSH
• geny rRNA MeSH
• histony metabolismus   MeSH
• lidé MeSH
• messenger RNA genetika   MeSH
• ribozomální DNA genetika   MeSH
• ribozomy genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• srovnávací studie MeSH
• Názvy látek
• chromatin MeSH
• histony MeSH
• messenger RNA MeSH
• ribozomální DNA MeSH

Epigenetic modifications, such as acetylation, phosphorylation, methylation, ubiquitination, and ADP ribosylation, of the highly conserved core histones, H2A, H2B, H3, and H4, influence the genetic potential of DNA. The enormous regulatory potential of histone modification is illustrated in the vast array of epigenetic markers found throughout the genome. More than the other types of histone modification, acetylation and methylation of specific lysine residues on N-terminal histone tails are fundamental for the formation of chromatin domains, such as euchromatin, and facultative and constitutive heterochromatin. In addition, the modification of histones can cause a region of chromatin to undergo nuclear compartmentalization and, as such, specific epigenetic markers are non-randomly distributed within interphase nuclei. In this review, we summarize the principles behind epigenetic compartmentalization and the functional consequences of chromatin arrangement within interphase nuclei.

• MeSH
• acetylace MeSH
• buněčné jádro metabolismus   ultrastruktura   MeSH
• chromatin ultrastruktura   MeSH
• chromozomální proteiny, nehistonové fyziologie   MeSH
• epigeneze genetická MeSH
• exprese genu MeSH
• histony genetika   metabolismus   MeSH
• homolog proteinu s chromoboxem 5 MeSH
• inhibitory histondeacetylas MeSH
• interfáze MeSH
• lidé MeSH
• lidské chromozomy X metabolismus   MeSH
• metylace MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• chromatin MeSH
• chromozomální proteiny, nehistonové MeSH
• histony MeSH
• homolog proteinu s chromoboxem 5 MeSH
• inhibitory histondeacetylas MeSH