Navigation Links
Regulating the nuclear architecture of the cell

ral region of the chromosome, the chromatin structure that plays a crucial role in chromosome segregation during cell division. What other functions abundant heterochromatin may perform are still an open question.

Even epigenetics ultimately has its roots in the genes; the researchers' first step was to identify which genes affect organization of the heterochromatin, then to identify the proteins expressed by these genes, and finally to learn how they act on the chromosomal material.

Steps along the path

Several genes previously identified in Drosophila as having a role in the suppression of gene expression, known as suppressors of variegation, were named Su(vars). The gene family known as Su(var)3-9 codes for proteins that chemically modify certain histones in the nucleosomes.

Su(var)3-9 proteins attach methyl groups to the histone labeled H3 at its ninth amino acid residue, which is a lysine. In the histone code the methylation target is known as H3K9, where K stands for lysine. Methylation of chromatin causes it to condense.

Another Su(var) gene, Su(var)2-5, makes a protein called HP1 that binds methylated H3K9 and Su(var)3-9 proteins; the effect is to further close up the chromatin, silencing genes by making access to DNA more difficult.

Other genes called E(var)s act to enhance variegation in Drosophila. One way they do this is by acetylation of the H3 histone's fourth amino acid, also a lysine. The effect is to open the chromatin at that site, making the DNA accessible.

"Acetylating H3K4 and demethylating H3K9 can activate a gene; deacetylating H3K4 and methylating H3K9 can silence it," Karpen explains. "Multiply modified at various locations, these histones are a major factor in changing the functions of chromatin, independent of DNA sequence."

Karpen and Peng studied fruit flies with mutant Su(var)3-9 genes, flies that could not produce HP1 proteins or the proteins
'"/>

Source:DOE/Lawrence Berkeley National Laboratory


Page: 1 2 3 4 5

Related biology news :

1. Researchers Discover Gene That Determines Asthma Susceptibility By Regulating Inflammation
2. Researchers solve mystery of how nuclear pores duplicate before cell division
3. First encyclopedia of nuclear receptors reveals organisms focus on sex, food
4. The evolution of food plants: Genetic control of grass flower architecture
5. The very unexpected life and death of a leukemic cell
6. Scientists reveal how disease bacterium survives inside immune system cell
7. Scientists devise way to measure RNA synthesis on the fly in a live cell
8. The making of a fat cell
9. Einstein scientists discover how protein crucial for motion is synthesised at the right place in the cell
10. Researchers identify new cord blood stem cell
11. The molecular post office inside the cell
Post Your Comments:
*Name:
*Comment:
*Email:
TAG: Regulating the nuclear architecture the cell

(Date:8/21/2014)... -- Nxt-ID, Inc. (OTCQB: NXTD), a biometric authentication company ... that its shares of common stock and the warrants ... proposed underwritten public offering of common stock and warrants ... Market, subject to closing of its proposed underwritten public ... trade under the symbol "NXTD" and "NXTDW," respectively. ...
(Date:8/21/2014)... use a previously unknown process for harvesting energy and ... a Penn State University scientist has discovered. The discovery ... plant growth, harvesting energy from the Sun, and understanding ... and other lakes worldwide. A paper describing the discovery ... edition of the journal Science on 21 ...
(Date:8/21/2014)... easy to ignore, but they are the ultimate source ... Humans are increasingly dependent on algae, too, to suck ... it to the bottom of the ocean. Now, by ... researchers have evidence showing that viruses infecting those algae ... even when all else stays essentially the same, and ...
Breaking Biology News(10 mins):Nxt-ID Approved for NASDAQ Capital Market Listing 2Nxt-ID Approved for NASDAQ Capital Market Listing 3Hot-spring bacteria reveal ability to use far-red light for photosynthesis 2Hot-spring bacteria reveal ability to use far-red light for photosynthesis 3Viruses take down massive algal blooms, with big implications for climate 2
... projecting how many people will get sick from seasonal ... season. The research, conducted by scientists at the National ... PLoS Currents: Influenza . Building on other ... the Influenza A virus is related to its novelty ...
... A team of UCSF researchers has engineered E. coli with ... program cells to communicate and perform computations. The work ... computers and creates a method to create circuits by "rewiring" ... cells into miniature computers, according to findings that will be ...
... now submerged beneath the Persian Gulf may have been home ... to an article published today in Current Anthropology ... University of Birmingham in the U.K., says that the area ... host to humans for over 100,000 years before it was ...
Cached Biology News:Researchers devise computer model for projecting severity of flu season 2UCSF team develops 'logic gates' to program bacteria as computers 2Lost civilization under Persian Gulf? 2
(Date:8/20/2014)... inventions licensed to biotechnology firms has revealed early ... these roadblocks, the researchers suggest that better communication ... could lead to faster commercialization down the road. ... made in university laboratories and licensed to biotechnology ... which have a high failure rate. But a ...
(Date:8/20/2014)... Mass. , Aug. 20, 2014  Decision Resources Group finds ... , Russia , India ... $1.6 billion in 2013, roughly equal to the size of ... however, the BRIC market will experience much faster growth as a ... aging population. Other key findings from Decision Resources Group,s ...
(Date:8/20/2014)... Stimulating nerves in your ear could improve the health ... at the University of Leeds used a standard TENS ... apply electrical pulses to the tragus, the small raised ... front of the ear canal. , The stimulation changed ... by reducing the nervous signals that can drive failing ...
(Date:8/19/2014)... Research and Markets  has announced the addition of the ... report to their offering. This report analyzes the ... by the following Product Segments: Media, Sera, and Reagents. ... Canada , Japan , Europe ... America . Annual estimates and forecasts are provided for the ...
Breaking Biology Technology:Early bottlenecks in developing biopharmaceutical products delay commercialization 2Early bottlenecks in developing biopharmaceutical products delay commercialization 3BRIC Vascular Access Device Market Valued at $1.6 Billion in 2013, Similar to the U.S. Market 2BRIC Vascular Access Device Market Valued at $1.6 Billion in 2013, Similar to the U.S. Market 3'Tickling' your ear could be good for your heart 2Global Cell and Tissue Culture Supplies - Strategic Business Report 2014 2
... 9, 2012 , Collaboration to create ... to active TB, enabling early treatment and disease outbreak prevention ... infectious disease portfolio with development of DNA-/RNA-based test that complements ... , New assay will use whole blood transcription profiling ...
... a report published in Nature Physics , they used ... magnetic. Graphene is a sheet of carbon atoms ... it exhibits no signs of the conventional magnetism usually associated ... remarkable properties won Manchester researchers the Nobel Prize in Physics ...
... Bioscience announced today that it has secured $47.5 million ... in the financing along with existing investors OrbiMed Advisors, ... with the financing, Josh Bilenker, M.D., Partner at Aisling ... of this round will support commercialization of the company,s ...
Cached Biology Technology:QIAGEN and Max Planck Institute for Infection Biology Collaborate to Develop Assay for Active TB Risk in Individuals With Latent Infection 2QIAGEN and Max Planck Institute for Infection Biology Collaborate to Develop Assay for Active TB Risk in Individuals With Latent Infection 3QIAGEN and Max Planck Institute for Infection Biology Collaborate to Develop Assay for Active TB Risk in Individuals With Latent Infection 4QIAGEN and Max Planck Institute for Infection Biology Collaborate to Develop Assay for Active TB Risk in Individuals With Latent Infection 5QIAGEN and Max Planck Institute for Infection Biology Collaborate to Develop Assay for Active TB Risk in Individuals With Latent Infection 6QIAGEN and Max Planck Institute for Infection Biology Collaborate to Develop Assay for Active TB Risk in Individuals With Latent Infection 7Graphene reveals its magnetic personality 2Roka Bioscience Secures $47.5 Million in Series D Financing 2
...
Luminometers...
... serial preparation of four ... cytosol/particulate/cytoskeleton/nuclear fractions from one ... can directly be used ... as 2-D gel/Western blot/gel-shift/translocation/enzyme ...
Mouse IL-31 RA Biotinylated Affinity Purified PAb...
Biology Products: