The genetic potentialities of an egg are transcribed, translated and built up into a temporal-spatial organization by epigenetic processes. How are these potentialities realized? Efforts to answer this question have naturally turned towards a study of the activity of the genetic material, which according to modern ideas is entirely composed of DNA. Stedmann & Stedmann (1950) originally suggeste...

Histones, nuclear proteins that normally package DNA in cells, are increasingly recognized as important mediators of inflammation and thrombosis, and have recently been linked to death in sepsis. They are released during inflammation by activated leukocytes, primarily neutrophils, as part of neutrophil extracellular traps (NETs). Although NETs play an important role in innate immunity, componen...

Patrick Cramer is a professor of Biochemistry at the Ludwig Maximilians University of Munich, Germany, and head of the Gene Center Munich. He is a structural biologist who has contributed to our understanding of the structure and function of RNAP II from yeast and its associated factors. In a recent study, his laboratory described the structure of RNAP II in complex with the initiation factor T...

Posttranslational modifications (PTMs) of histone proteins, such as acetylation, methylation, phosphorylation, and ubiquitylation, play essential roles in regulating chromatin dynamics. Combinations of different modifications on the histone proteins, termed 'histone code' in many cases, extend the information potential of the genetic code by regulating DNA at the epigenetic level. Many PTMs occ...

Exhaustive digestion of chromatin with trypsin leads to the cleavage of only 20-30 amino acids from each of histones III (f3), IV (f2a1), IIb2 (f2b), and IIb1 (f2a1), the remainder of these chains being resistant. This resistance is not altered by removing the histones from the DNA with 2 M NaCl, but is dramatically reduced in 6 M urea. Histones III, IV, IIb2, and possibly IIb1 are cleaved at t...