Featured Research

from universities, journals, and other organizations

Scientists discover new mechanism that preserves genomic integrity and is abnormal in the rare DiGeorge syndrome

Date:
October 9, 2013
Source:
University of Granada
Summary:
Scientists have described a molecular mechanism that facilitates the defense of the human genome against "bombarding" by mobile DNA sequences. Abnormalities in the mechanism could be responsible for some symptoms of DiGeorge syndrome, a rare disease. The research could in the future help develop new therapies against the disease, which is caused by the microdeletion of a small part of chromosome 22.

An international team of scientists -- including researchers at GENYO, the Centre for Genomics and Oncological Research (Pfizer-University of Granada- Andalusian Regional Government) -- has described a molecular mechanism that facilitates the defence of the human genome against "bombarding" by mobile DNA sequences. Abnormalities in the mechanism could be responsible for some symptoms of DiGeorge syndrome, a rare disease. The research could in the future help develop new therapies against the disease, which is caused by the microdeletion of a small part of chromosome 22.

The study, published this week in the journal Nature Structural and Molecular Biology describes a sophisticated mechanism that enables all of our cells to control the uncontrolled movement of mobile DNA in our genomes. In patients with DiGeorge syndrome, the cells present abnormalities in the control mechanism. Currently, the research team are trying to generate stem cells that "suffer" from the disease from cells donated by patients who have it -- which would enable them to clarify the molecular base of this complex pathology.

DiGeorge syndrome, also known as deletion 22q11.2, is the most common genetic disease caused by a chromosome microdeletion in humans. It has an estimated prevalence of 1 in 4000 births and symptoms vary greatly. Typically, these affect the heart and immune system, as well as presenting as learning difficulties, mental retardation and psychiatric disorders.

The disease is characterized by absence of the "Microprocessor" protein complex, which means these patients lack a 'vigilante' gene to watch out for repeated sequences and, therefore, are potentially susceptible to being bombarded by these DNA fragments.

"Microprocessor" is the key

Sara R. Heras -- co-author of the study and GENYO researcher -- explains that all our cells contain "Microprocessor," a protein complex whose known function at the moment is that of generating small regulatory molecules of ribonucleic acid (RNA), known as microRNAs. "Our study has shown that this complex also acts as 'vigilante' and defends the integrity of the human genome. Hence, these proteins are capable of recognizing and fragmenting the repeated DNA sequences that escape previous control mechanisms, thus preventing them from replicating and introducing themselves into the genome."

In Nature Structural and Molecular Biology, Sara R. Heras, Sara Macías and their collaborators have described a new mechanism by which most human cells can avoid being bombarded by these DNA fragments. This study has been conducted in the laboratory headed by Dr. José Luis García Pérez in GENYO (Granada) in collaboration with Dr. Javier Cáceres "Medical Research Council-Human Genetic Unit" in Edinburgh (United Kingdom) and Dr. Eduardo Eyras' laboratory at the Universidad Pompeu Fabra, Barcelona.

Embryonic model

In these new studies, the authors are using an embryonic model of induced pluripotent stem cells (iPSCs). That is, from cells donated by patients with DiGeorge syndrome, stem cells with the disease are generated. This is an ideal model to determine the impact of the repeated sequences from which the deletion that causes this pathology are generated: in other words, the embryonic stage. It is foreseen that these studies will clarify the molecular base for this highly complex disease, as well as permit the long-term development of new therapies for its treatment.


Story Source:

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


Journal Reference:

  1. Sara R Heras, Sara Macias, Mireya Plass, Noemí Fernandez, David Cano, Eduardo Eyras, José L Garcia-Perez, Javier F Cáceres. The Microprocessor controls the activity of mammalian retrotransposons. Nature Structural & Molecular Biology, 2013; 20 (10): 1173 DOI: 10.1038/nsmb.2658

Cite This Page:

University of Granada. "Scientists discover new mechanism that preserves genomic integrity and is abnormal in the rare DiGeorge syndrome." ScienceDaily. ScienceDaily, 9 October 2013. <www.sciencedaily.com/releases/2013/10/131009100002.htm>.
University of Granada. (2013, October 9). Scientists discover new mechanism that preserves genomic integrity and is abnormal in the rare DiGeorge syndrome. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2013/10/131009100002.htm
University of Granada. "Scientists discover new mechanism that preserves genomic integrity and is abnormal in the rare DiGeorge syndrome." ScienceDaily. www.sciencedaily.com/releases/2013/10/131009100002.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) — The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com
Another Study Suggests Viagra Is Good For The Heart

Another Study Suggests Viagra Is Good For The Heart

Newsy (Oct. 20, 2014) — An ingredient in erectile-dysfunction medications such as Viagra could improve heart function. Perhaps not surprising, given Viagra's history. Video provided by Newsy
Powered by NewsLook.com
Ebola Worries End for Dozens on U.S. Watch Lists

Ebola Worries End for Dozens on U.S. Watch Lists

Reuters - US Online Video (Oct. 20, 2014) — Forty-three people who had contact with Thomas Eric Duncan, the first person diagnosed with Ebola in the U.S., were cleared overnight of twice-daily monitoring after 21 days of showing no symptoms. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
CDC Calls for New Ebola Safety Guidelines

CDC Calls for New Ebola Safety Guidelines

AP (Oct. 20, 2014) — Centers for Disease Control and Prevention Director Dr. Tom Frieden laid out new guidelines for health care workers when dealing with the deadly Ebola virus including new precautions when taking off personal protective equipment. (Oct. 20) Video provided by AP
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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