Search results
Results from the WOW.Com Content Network
Whereas DNA methylation is not necessary per se for transcriptional silencing, it is thought nonetheless to represent a "locked" state that definitely inactivates transcription. In particular, DNA methylation appears critical for the maintenance of mono-allelic silencing in the context of genomic imprinting and X chromosome inactivation.
Transcription can be silenced by histone modification (deacetylation and methylation), RNA interference, and/or DNA methylation. [41] The gene expression patterns that define cell identity are inherited through cell division. [1] This process is called epigenetic regulation.
In one mechanism, CpG methylation influences binding of most transcription factors to DNA—in some cases negatively and in others positively. [31] In addition, often they are at the end of a signal transduction pathway that functions to change something about the factor, like its subcellular localization or its activity.
Histone methylation is a process by which methyl groups are transferred to amino acids of histone proteins that make up nucleosomes, which the DNA double helix wraps around to form chromosomes. Methylation of histones can either increase or decrease transcription of genes, depending on which amino acids in the histones are methylated, and how ...
The function of DNA strands (yellow) alters depending on how it is organized around histones (blue) that can be methylated (green).. In biology, the epigenome of an organism is the collection of chemical changes to its DNA and histone proteins that affects when, where, and how the DNA is expressed; these changes can be passed down to an organism's offspring via transgenerational epigenetic ...
In mammals, DNA methylation occurs almost exclusively at a cytosine that is followed by a guanine. DNA methylation is a widespread mechanism for epigenetic influence on gene expression and is seen in bacteria and eukaryotes and has roles in heritable transcription silencing and transcription regulation. Methylation most often occurs on a ...
EGR1 protein is a particular transcription factor that is important for regulation of methylation of CpG islands. An EGR1 transcription factor binding site is frequently located in enhancer or promoter sequences. [26]
The cis position induces compact histones and decreases the ability of proteins to bind to the DNA, thus preventing methylation of K36 and decreasing gene transcription. Conversely, the trans position of P38 promotes a more open histone conformation, allowing for K36 methylation and leading to an increase gene transcription.