Featured Research

from universities, journals, and other organizations

Genetic sequence that helps to coordinate synthesis of DNA-packaging proteins identified

Date:
March 24, 2013
Source:
University of North Carolina Health Care
Summary:
Research conducted in fruit flies has pinpointed a specific DNA sequence that both triggers the formation of the "histone locus body" and turns on all the histone genes in the entire block.

This is a micrograph of a nuclei from a fruit fly salivary gland showing the endogenous histone locus body (large arrow) and HLB formed on the inserted histone genes (small arrow).
Credit: Deirdre Tatomer, UNC Dept. of Biology.

Research conducted in fruit flies at the University of North Carolina School of Medicine has pinpointed a specific DNA sequence that both triggers the formation of the "histone locus body" and turns on all the histone genes in the entire block.

Every time a cell divides it makes a carbon copy of crucial ingredients, including the histone proteins that are responsible for spooling yards of DNA into tight little coils. When these spool-like proteins aren't made correctly, it can result in the genomic instability characteristic of most birth defects and cancers.

Seven years ago, Dr. Joe Gall of the Carnegie Institute in Baltimore, Md. and coworkers noticed an aggregation of molecules along a a block of genome that codes for the critical histones, but they had no idea how this aggregate or "histone locus body" was formed.

Now, research conducted in fruit flies at the University of North Carolina School of Medicine has pinpointed a specific DNA sequence that both triggers the formation of this "histone locus body" and turns on all the histone genes in the entire block.

The finding, published March 25, 2013 in the journal Developmental Cell, provides a model for the coordinated synthesis of histones needed for assembly into chromatin, a process critical to keeping chromosomes intact and passing genetic information from generation to generation.

"Our study has uncovered a new relationship between nuclear architecture and gene activity," said senior study author Bob Duronio, PhD, professor of biology and genetics at UNC. "In order to make chromosomes properly, you need to make these histone building blocks at the right time and in the right amount. We found that the cell has evolved this complex architecture to do that properly, and that involves an interface between the assembly of various components and the turning on of a number of genes."

In the fruit fly, as in the human, the five different histone genes exist in one long chunk of the genome. The "histone locus" in flies contains 100 copies of each of the five genes, encompassing approximately 500,000 nucleotides of A's, C's, T's and G's. The proteins required for making the histone message -- a process that must happen every time a new strand of DNA is copied -- come together at this "histone locus" to form the "histone locus body."

Duronio and co-senior study author William Marzluff, PhD, Kenan Distinguished Professor of Biochemistry and Biophysics, wanted to figure out how these factors knew to meet at the histone locus.

They inserted different combinations of the five histone genes into another site of the genome, and looked to see which combinations recruited a new histone locus body. The researchers found that combinations that contained a specific 300 nucleotide sequence -- the region between the H3 and H4 histone genes -- formed a histone locus body. In contrast, combinations of genes that lacked this sequence did not form the body. They went on to show that this sequence turned on not only the H3 and H4 genes in its direct vicinity, but also other histone genes in the block.

Though the research was conducted entirely in fruit flies, it may lend insight into mechanisms that keep the genome from becoming unstable -- and causing early death or illness -- in higher organisms.

"Humans and flies have these very same histone genes. They have the same proteins in the histone locus body. So understanding precisely how this works in flies will help us understand cell division in humans," said Marzluff.


Story Source:

The above story is based on materials provided by University of North Carolina Health Care. Note: Materials may be edited for content and length.


Cite This Page:

University of North Carolina Health Care. "Genetic sequence that helps to coordinate synthesis of DNA-packaging proteins identified." ScienceDaily. ScienceDaily, 24 March 2013. <www.sciencedaily.com/releases/2013/03/130324140458.htm>.
University of North Carolina Health Care. (2013, March 24). Genetic sequence that helps to coordinate synthesis of DNA-packaging proteins identified. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/2013/03/130324140458.htm
University of North Carolina Health Care. "Genetic sequence that helps to coordinate synthesis of DNA-packaging proteins identified." ScienceDaily. www.sciencedaily.com/releases/2013/03/130324140458.htm (accessed August 29, 2014).

Share This




More Plants & Animals News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Raw: Australian Sheep Gets Long Overdue Haircut

Raw: Australian Sheep Gets Long Overdue Haircut

AP (Aug. 28, 2014) Hoping to break the record for world's wooliest, Shaun the sheep came up 10 pounds shy with his fleece weighing over 50 pounds after being shorn for the first time in years. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Minds Blown: Scientists Develop Fish That Walk On Land

Minds Blown: Scientists Develop Fish That Walk On Land

Newsy (Aug. 28, 2014) Canadian scientists looking into the very first land animals took a fish out of water and forced it to walk. Video provided by Newsy
Powered by NewsLook.com
Huge Ancient Wine Cellar Found In Israel

Huge Ancient Wine Cellar Found In Israel

Newsy (Aug. 28, 2014) An international team uncovered a large ancient wine celler that likely belonged to a Cannonite ruler. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins