MetüülCpG

MetüülCpG refers to a modified form of cytosine, one of the four nucleobases in DNA. In this modification, a methyl group is attached to the carbon-5 position of the cytosine ring, forming 5-methylcytosine. This methylation primarily occurs at CpG dinucleotides, where a cytosine is immediately followed by a guanine in the DNA sequence.

CpG islands are regions of the genome that are particularly rich in CpG dinucleotides. While CpG dinucleotides are generally underrepresented in the mammalian genome, CpG islands are often found in the promoter regions of genes. DNA methylation is a crucial epigenetic mechanism that plays a significant role in gene regulation.

The methylation of CpG sites within gene promoters is typically associated with gene silencing. This repression can occur through several mechanisms, including blocking the binding of transcription factors to the DNA or by recruiting methyl-CpG-binding proteins that in turn recruit repressor complexes. These epigenetic changes are heritable through cell division, allowing for long-term regulation of gene expression without altering the underlying DNA sequence.

MetüülCpG modifications are vital for various biological processes, including embryonic development, genomic imprinting, and X-chromosome inactivation. Aberrant DNA methylation patterns are implicated in the development of diseases, most notably cancer, where hypermethylation of tumor suppressor gene promoters can lead to their silencing and contribute to uncontrolled cell growth. Understanding metüülCpG and its role in epigenetics is an active area of research with implications for diagnostics and therapeutics.