Chromatin regulators

A model called histone code theory includes more aspects of chromatin regulation which have been identified. The histone code theory predicts that histone acetylation and other posttranslational histone modifications serve as binding sites for regulatory proteins which mediate processes like gene transcription upon recruitment (see Fig. 2b) [3]. In this context histone modifications can be understood as... 

The striking similarities between yeast and higher eukaryotes in H2A.Z metabolism suggest that the fundamental molecular mechanisms of chromatin regulation by this variant are mostly conserved. However, the readout of H2A.Z in... 

Aggarwal BD, Calvi BR (2004) Chromatin regulates origin activity in Drosophila follicle cells. Nature 430 372-376... 

Takeuchi T, Watanabe Y, Takano-Shimizu T, Kondo S. 2006. Roles of jumonji and jumonji family genes in chromatin regulation and development. Dev Dyn 235 2449-2459. 

Berger SL (2007) The complex language of chromatin regulation during transcription. Nature 447(7143) 407-412... 

Tsankova NM et al (2006) Sustained hippocampal chromatin regulation in a mouse model of depression and antidepressant action. Nat Neurosci 9(4) 519-525... 

Finding the bromo domain in so many chromatin-regulating proteins reveals a potential central regulation mechanism that mediates... 

Figure 34. First insights into mesogenic chromatin regulations superhelical DNA chromatin arrangement [29 g, h, 33 f] winding up chromatin packages by Bonnet transformation operation modes [77h].

Nucleic acid liquid crystals - from phase elucidation to chromatin regulation a) F. Livolant,... 

Histone acetylation is a reversible and covalent modification of histone proteins introduced at the e-amino groups of lysine residues. Histones and DNA form a complex - chromatin - which condenses DNA and controls gene activity. Current models interpret histone acetylation as a means to regulate chromatin activity. 

The exact role of individual histone acetylations will have to be determined in the context of other modifications and the number of lysine residues effected. However, the general importance of histone acetylation as a regulator for chromatin activity is undisputed. This leads to the intriguing possibility to develop drugs that target histone acetylation for therapeutic purposes. The primary targets for drug development are the histone acetyl transferases (HATs) and the histone deacetylases (HDACs) which introduce and remove histone acetylations [2, 3]. 

Turner BM (2001) Chromatin and Gene Regulation. Blackwell Science Ltd., Oxford... 

Histone tails are the N-terminal regions of histones which reach outside the nucleosomes. They are not essential for the formation in of nucleosomes but are required for the formation of higher-order chromatin structures. The histone tails are also known to be heavily posttranslationally modified by acetylation, phosphorylation, methylation, etc. and are important for the regulation of gene activity. 

The multiple sites that serve as origins for DNA replication in eukaryotes are poorly defined except in a few animal viruses and in yeast. However, it is clear that initiation is regulated both spatially and temporaUy, since clusters of adjacent sites initiate rephcation synchronously. There are suggestions that functional domains of chromatin replicate as intact units, implying that the origins of rephcation are specificaUy located with respect to transcription units. 

Narlikar GJ et al Cooperation between complexes that regulate chromatin structure and transcription. Cell 2002 108 475. 

All steps—from changes in DNA template, sequence, and accessibility in chromatin to RNA stability—are subject to modulation and hence are potential control sites for eukaryotic gene regulation. 

WUson CJ, Chao DM, Imbalzano AN, Schnitzler GR, Kingston RE, Young RA (1996) RNA polymerase II holoenzyme contains SWI/SNF regulators involved in chromatin remodeling. Cell 84(2) 235-244... 

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