Rearrangements of the mixed lineage leukemia gene, MLL, are associated with aggressive leukemias in both children and adults. Researchers at the University of Pennsylvania School of Medicine have found that one portion of the MLL protein is an enzyme that "edits" the so-called histone code, a series of modifications to proteins associated with DNA that influence how and when certain genes are turned on and off. Their findings are presented in the November issue of Molecular Cell.
When functioning properly, the MLL protein regulates the expression of Hox genes, which play a role in cell growth and development. In some leukemias MLL is rearranged so that the cells are unable to turn off Hox genes. The Penn investigators found that a portion of the MLL protein binds directly to the Hox genes and edits the histone code at these sites. A rearranged form of MLL that causes leukemia also upregulated Hox expression but with a different "code". Presumably the differences in the pattern of histone modifications accounts for their deregulated expression in leukemia.
The histone code hypothesis was first outlined by Dr. C. David Allis and colleagues, of the University of Virginia Health System, a co-author on this paper. The theory, which rapidly is gaining acceptance, postulates that expression of certain regions of DNA is turned on and off by modifying portions of histone proteins or DNA. Modified histones and DNA attract the cells gene-reading machinery via specific interactions with these elements of the histone code.
Greg Lester | EurekAlert!
Neutrons produce first direct 3D maps of water during cell membrane fusion
21.09.2018 | DOE/Oak Ridge National Laboratory
Narcolepsy, scientists unmask the culprit of an enigmatic disease
20.09.2018 | Universitätsspital Bern
The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.
This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.
Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...
Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.
"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...
A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.
Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...
Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.
An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...
03.09.2018 | Event News
27.08.2018 | Event News
17.08.2018 | Event News
21.09.2018 | Trade Fair News
21.09.2018 | Earth Sciences
21.09.2018 | Health and Medicine