Aberrant methylation patterns of genomic DNA are well-studied epigenetic mutations in cancer. Hypermethylation of CpG islands in tumor-suppressor genes promotes oncogenesis and hypomethylation of global genomic DNA affects genomic stability. Cancer is recognized as a genetic and epigenetic disease. However, it is not clear how epigenetic regulatory factors, including histone modification enzyme...

In mammalian cells, genomic DNA is packaged with histone proteins and condensed into chromatin. To gain access to the DNA, chromatin remodelling required that enhanced through post-translational modifications, which subsequently stimulate processes including repair transcription. Histone acetylation one of most well understood modifications controlled by acetyltransferases (HATs) deacetylases (...

sideration as DNA methylation patterns may be reversible and changeable under certain physiological and pathological conditions. This idea is supported by the fact that differentiated cells are still potent enough to be converted into iPS cells, presumably coupling with altered DNA methylation pattern. Beyond canonical epigenomic modification, the current view of the epigenome includes histone ...

Many cellular and secreted proteins are chemically modified after their translation is completed. The covalent linkage of a polypeptide chain (modifier) to a substrate protein is a special case of post-translational modification. In the late seventies it was observed that ubiquitin, a small modifier, marks short-lived proteins for degradation by the 26S proteasome. Over the last decade many oth...

Nuclear hormone receptors (NRs) are transcription factors responsible for mediating the biological effects of hormones during development, metabolism, and homeostasis. Induction of NR target genes is accomplished through the assembly of hormone-bound NR complexes at target promoters and coincides with changes in histone modifications that promote transcription. Some coactivators and corepressor...

Epigenetic information refers to heritable changes in gene function that are stable between cell divisions but which is not a result of changes in the DNA sequence. Part of the epigenetic mechanism has been ascribed to modifications of histones or DNA that affects the transcription of specific genes. In this context, post-translational modifications of histone tails, in particular methylation o...

Rates of histone acetylation and deacetylation in nuclei from fetal, adult, and two kinds of neoplastic rat hepatocytes were examined. Histone acetylation in isolated nuclei was measured in the presence of 6 mM sodium n-butyrate, a potent inhibitor of deacetylase, and in the absence of the inhibitor. The deacetylase activity was estimated from the difference between the rates with or without th...

Cell transformation is clearly linked to epigenetic changes. However, the role of the histone-modifying enzymes in this process is still poorly understood. In this study, we investigated the contribution of the histone acetyltransferase (HAT) enzymes to Ras-mediated transformation. Our results demonstrated that lysine acetyltransferase 5, also known as Tip60, facilitates histone acetylation of ...

The delivery of site-specific post-translational modifications to histones generates an epigenetic regulatory network that directs fundamental DNA-mediated processes and governs key stages in development. Methylation of histone H4 lysine-20 has been implicated in DNA repair, transcriptional silencing, genomic stability and regulation of replication. We present the structure of the histone H4K20...