from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of several small, basic proteins most commonly found in association with the DNA in the chromatin of eukaryotes.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of various simple water soluble proteins that are rich in the basic amino acids lysine and arginine and are complexed with DNA in the nucleosomes of eukaryotic chromatin.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a simple protein containing mainly basic amino acids; present in cell nuclei in association with nucleic acids
Sorry, no etymologies found.
There is a sophisticated code, known as the histone code, that directs the decisions as to which parts of the DNA sequence are transcribed into mRNA and which are not.
Typically, the gossamer thread of DNA is wound around a spool of protein called histone; when this second class of enzymes strips away part of the packaging, the DNA becomes so tightly wound up that it can't loosen up enough to be read by the cell.
A group of agents called histone deacetylase inhibitors can help here, says Sharon Lewin, director of the infectious-diseases unit at Alfred Hospital in Melbourne, who is about to start a clinical trial of a histone-deacetylase inhibitor called SAHA.
While they are powerful killers of some breast cancer cells, new drugs called histone deacetylase inhibitors, or HDAC inhibitors, also increase self-digestion, or autophagy, in surviving, mega-stressed cells.
"In addition to this, we have also shown that when the neuroblastoma and breast cancer cells are treated with a new class of anti-cancer drugs called histone deacetylase inhibitors (HDACIs), they are able to turn the TG2 gene back on, which then inhibits tumour growth."
Together, they designed and used a DNA-cutting enzyme called a zinc finger nuclease to chemically tag histone H3. 3 and distinguish it from other histone proteins in mouse embryonic stem cells.
They showed how cocaine affects an epigenetic process (a process capable of influencing gene expression without changing a gene's sequence) called histone methylation.
The interaction between the active form of the frataxin gene and the inactive (silenced) form is mediated by enzymes called histone deacetylases (HDAC).
There were entire classes of new druggable targets waiting to be discovered, he said, including those in a class he studied, called histone methyltransferases (HMTs), which regulate gene expression by adding methyl groups to selected lysine or arginine residues on histones.
He described the success of a drug called Zolinza, which takes the brakes off silenced genes by inhibiting a type of enzyme called histone deacetylase (HDAC); Zolinza was bought by Merck for an estimated $145 million in 2004, and was approved to treat cutaneous T-cell lymphoma the year before.
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