Transcription epigenetic regulation

There are two major mechanisms of epigenetic regulation, methylation of cytosines in the DNA sequence and modification of the histone proteins that the DNA is wrapped around. The co-ordination of both mechanisms results in dramatic changes in remodeling of chromatin and altered gene transcription. 

NUCLEAR RECEPTOR COREGULATORS AND EPIGENETIC REGULATION OF GENE TRANSCRIPTION... 

V. The Histone Code Insights into Epigenetic Regulation of Transcription. 194... 

Mukherjee K, Fischer R, Vilcinskas A. Histone acetylation mediates epigenetic regulation of transcriptional reprogramming in insects during metamorphosis, wounding and infection. Front Zool. 2012 9(1) 25. doi 10.1186/1742-9994-9-25. 

P450 2A13 transcription involves CcATT/en-hancer-binding protein (C/EBP) transcription factors [502]. This interaction is believed to be responsible for olfactory mucosa-specific expression in humans. In addition, tliere is evidence for epigenetic regulation of P450 2A13 expression, at both the levels of DNA methylation and histone acetylation [502, 503]. 

Xie Y Ke S, Ouyang N, He J, Xie W, Bedford MT, Tian Y (2009) Epigenetic regulation of transcriptional activity of pregnane X receptor by protein aiginine methyltransferase 1. J Biol Chem 284 9199-9205... 

SANTOS p, ARUMEMi F, PARK Ks, BORGHESi L, MiLCAREK c (2011), Transcriptional and epigenetic regulation of B cell development , Immunol Res, 50,105-12. 

In higher eukaiyotes, most of the chromosomal DNA carries 5-methyl-cytidine residues located in CpG sequence motives. There is a close correlation between transcriptional inactivation and methylation. On the other hand, considerable evidence shows that regions of DNA that are actively engaged in transcription lack 5-methyl-cytidine nucleotides in CpG motivs. Hence DNA methylation is a means how cells regulate gene expression. DNA methylation which is catalyzed by DNA methyltransferases is the best characterized epigenetic mechanism. 

Figure 17.4. Epigenetics in the nervous system. Regulation occurs in response to synaptic inputs and/or other psychosocial-environmental stimuli. The external stimuli result in changes in the transcriptional profile of the neuron and eventually affects neural function(s). Many disorders of human cognition might involve dysfunction of epigenetic tagging. (See color insert.)...

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