Histone acetylation and Histone methylation

Acetylation of explicit residues of histones is associated with gene activity and may play elementary role in transcriptional regulation. Bromodomains, motifs found in several eukaryotic transcription factors, exclusively interact with acetyl-lysines in histones. p300 is functionally conserved transcriptional coactivators for various transcription factors and have intrinsic acetyltransferase activity. The covalent alteration of histone tails has regulatory roles in various nuclear processes, such as organization of transcription and mitotic chromosome condensation. Among the different groups of enzymes identified to catalyze the covalent modification, the most topical additions are the histone methyltransferases (HMTases), whose functions are now being characterized. G9A is a novel mammalian HMTase that prefer lysine. Specific chromosome translocations commonly found in human leukemia engross rearrangements of genes which are implicated in the regulation of hematopoiesis. Further, the detail shows that the chromosome translocations often results in the expression of gene products.