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The concept of epigenetics has been known about since the 1940s, but it is only in the last 10 years that research has shown just how wide ranging its effects are. It is now a very widely-used term, but there is still a lot of confusion surrounding what it actually is and does.
Epigenetics is a new textbook that brings together the structure and machinery of epigenetic modification, how epigenetic modification controls cellular functions, and the evidence for the relationship between epigenetics and disease. It is a valuable source of information about all aspects of the subject for undergraduate students, graduate students, and professionals.
proteins 29 Chromatin remodeling is mediated by the SWI/SNF family of proteins in eukaryotes 30 Chromatin remodeling by SWI/SNF works by repositioning nucleosomes 31 Transcription factor binding sites are often located in regions of low nucleosome occupancy 32 CHROMATIN MODIFICATION 33 Spontaneous conformational changes and covalent modifications can also expose DNA to transcription factors 33 Epigenetic modification of DNA or histones regulates nucleosome occupancy and repositioning
in mice. This region encodes six miRNAs (miR-290 through miR-295) that share a 5 -proximal AAGUGC motif. The cluster (for brevity referred to as the miR-290 cluster) increases its expression during preimplantation development and remains high in undifferentiated ES cells, but decreases after ES cell differentiation. In undifferentiated ES cells, the miR-290 cluster miRNAs suppress a transcriptional repressor that targets genes encoding de novo DNA methyltransferases, with the result that DNMT3A
by alanine. Strains of the yeast Saccharomyces cerevisiae in which lysines 6, 7, 16, and 17A have been replaced showed enhanced basal transcription of multiple genes. This supports the view that SUMOylation is a repressive histone modification and that the sites occupied by this modification are frequently those that are occupied by acetyl groups during active transcription of the target gene. Exactly how the SUMO moiety is able to repress gene activity is not clear. It is easy to imagine that
from lysine The SUMO modification pathway is an example of a reversible system that is controlled by a series of on and off enzymes. The removal step is quite simple because only two SUMO-deconjugating enzymes have been discovered in simpler organisms such as yeast, and a total of only six in humans. The SUMO removal system makes use of the SUMO-specific proteases. These have a catalytic domain characterized by the catalytic triad (histidine, aspartate, and cysteine), as shown in the S.
Biol 143:41–53 (doi:10.1016/S0022-5193(05)80287-5). Moazed D (2011) Mechanisms for the inheritance of chromatin states. Cell 146:510–518 (doi:10.1016/j.cell.2011.07.013). Monk M (1990) Variation in epigenetic inheritance. Trends Genet 6:110–114. Roberts AR, Huang E, Jones L et al. (2013) Non-telomeric epigenetic and genetic changes are associated with the inheritance of FURTHER READING shorter telomeres in mice. Chromosoma Jul 18 [Epub ahead of print] doi:10.1007/s00412-013-0427-8). Sarkies P &