About Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Researchers Purify Protein That Could Regulate Male Hormones

by Medindia Content Team on May 7, 2006 at 4:39 PM
Font : A-A+

Researchers Purify Protein That Could Regulate Male Hormones

Researchers at University of North Carolina at Chapel Hill have managed to purify a protein and have shown that it can affect gene activity by modifying a molecular pathway that was previously thought to be permanent.

The findings, published today (May 5) in the journal Cell, also show that the new protein plays a role in gene activation mediated by androgen receptor, a protein that responds to androgen hormones. In this regard, the novel protein may figure in the development of prostate cancer. Androgens, particularly testosterone and dihydrotestosterone, determine male secondary sex characteristics and stimulate prostate cell growth. Lowering androgen levels usually can make prostate cancers shrink or grow more slowly.

Advertisement

In the study, the researchers said the new protein called JHDM2A, like the protein they reported on in the journal Nature in December 2005, is able to remove a methyl group from histone H3, one of four histone proteins bound to all genes.

"Human genes are so tightly compact within the nucleus that if the DNA of a single cell were unwound and stretched, it would be a line of about two meters in length. Histones are necessary to package the DNA so that it fits inside a cell's nucleus," said senior author Dr. Yi Zhang, professor of biochemistry and biophysics at UNC's School of Medicine and the university's first Howard Hughes Medical Institute investigator.
Advertisement

Zhang also is a member of the UNC Lineberger Comprehensive Cancer Center.

Because histones are so intimately associated with DNA, even slight chemical alterations of these proteins can have profound effects on nearby genes. Depending on their precise location and how many methyl groups are added, the presence of alterations can either turn on or turn off a gene.

In the study, Zhang learned that the JHDM2A specifically removes methyl-groups from lysine 9 of histone H3. "The important thing is that H3K9 demethylation has been linked to transcription silencing, turning genes off. So that led us to pay attention to this protein's role in reversing whatever function K9 methylation might have," Zhang said.

In their experiments, the researchers learned that consistent with reversing a marker of gene silencing (H3K9 methylation), the protein functions as a co-activator - in this case, a co-activator for the androgen receptor target genes.

Using human tissue cultures, including prostate cells, Zhang and his colleagues found that over-expression of JHDM2A greatly reduced H3K9 methylation level and led to upregulation, or switching on, of androgen receptor target genes. In contrast, when methylation was increased, the gene was silenced - switched off.

It remains unclear for how many different human genes JHDM2A is a primary regulator. According to Zhang, the new findings indicate that the protein will provide another tool to enlist in studies of gene expression regulation. "Given the androgen receptor link, we're now trying to identify the downstream target genes, as well as its role in prostate cancer," he said.

"Theoretically, this protein is a very important tool for gene expression studies. Practically, it provides a potential target for prostate cancer because of its enzymatic activity. And it is enzymatic activity that's the favorite target of drug development."

Contact:
Leslie H. Lang
llang@med.unc.edu
919-843-9687
University of North Carolina School of Medicine
Source: Eurekalert
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
What's New on Medindia
Vaccination  And Counter  Measures Against  Monkeypox
Indian Railways Special Concession on Health Grounds
COVID Toes
View all
Recommended Reading
News Archive
Date
Category
News Category

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Diet and Nutrition Tips for Athletes 

Most Popular on Medindia

Turmeric Powder - Health Benefits, Uses & Side Effects Daily Calorie Requirements Post-Nasal Drip Drug - Food Interactions Find a Doctor How to Reduce School Bag Weight - Simple Tips Color Blindness Calculator Loram (2 mg) (Lorazepam) Vent Forte (Theophylline) The Essence of Yoga

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2022

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use
open close
ASK A DOCTOR ONLINE