Featured Research

from universities, journals, and other organizations

UT Southwestern Researchers Find Lever Involved In Ultrviolet-Ray Sensitivity

Date:
June 22, 1999
Source:
University Of Texas Southwestern Medical Center At Dallas
Summary:
Investigation of two important cell systems has revealed that a large protein complex, previously thought to mainly regulate protein degradation, also plays a significant role in sensitivity to cancer-causing ultraviolet light.

DALLAS - June 18, 1999 - Investigation of two important cell systems has revealed that a large protein complex, previously thought to mainly regulate protein degradation, also plays a significant role in sensitivity to cancer-causing ultraviolet light.

Related Articles


UT Southwestern Medical Center at Dallas researchers reported the findings in today's issue of Molecular Cell. The scientists reached their conclusion when they joined their studies of a biological machine called the proteasome and the protein Rad23, which is involved in repair of DNA damaged by ultraviolet light. If the repair machine fails to work, as in the disease xeroderma pigmentosum, mutations occur that lead to skin cancer, said Steven Russell and Dr. Simon Reed, two of the paper's authors.

"Clearly these two systems have important roles in human health and disease," said Russell of the work, done in vitro and in live yeast, which involved genes also found in humans. "This is a seminal finding about the relationship between the proteasome and the repair complex. The knowledge will lead to new insights into both systems."

The team of investigators discovered that by deleting a part of Rad23, a component of the nucleotide excision repair (NER) machinery, they could increase sensitivity to UV radiation. This means for DNA repair to work properly, that particular domain of Rad23, which binds to the proteasome, must be present. They also showed that inhibiting an ATPase, one of the proteasome's energy sources, diminishes NER activity, thus increasing UV sensitivity.

"If you hit the yeast with high enough levels of light, they get so much DNA damage that they die. Lower amounts of UV rays also will cause damage but they can repair it and survive, much the way people do if their systems are functioning normally," Reed said. "This work shows that mutations in the proteasome can cause yeast to be less resistant to ultraviolet light, which supports the idea that the proteasome is involved in repair."

Next the researchers will study each step in the repair process to uncover when the defect that allows UV sensitivity occurs. If they can determine exactly how the mechanism works, it may be possible to manipulate it for people who are genetically predisposed to skin cancer.

The researchers said they believe part of the secret lies in how the proteasome affects proteins. "It's useful to think of these proteins as machines cranking through the steps: The DNA is pulled apart into separate strands, cuts are made, and the damaged part is taken out. This process probably requires a change in the shape of the repair proteins, just like a lever moving on a piece of industrial equipment," said Russell. "We believe the proteasome may cause those shape changes by using energy from the ATPases. We want to know what proteins are changing shape and what the changes are."

Russell is working on his medical degree and doctorate in UT Southwestern's Medical Scientist Training Program. Reed is a postdoctoral fellow in pathology. Other researchers involved in the study were: Dr. Stephen Johnston, professor of biochemistry and internal medicine and co-director of the Center for Biomedical Inventions; Dr. Errol Friedberg, chairman of pathology; and Dr. Wenya Huang, pathology postdoctoral fellow.

Funds from the National Institutes of Health and the Perot Foundation supported this work.


Story Source:

The above story is based on materials provided by University Of Texas Southwestern Medical Center At Dallas. Note: Materials may be edited for content and length.


Cite This Page:

University Of Texas Southwestern Medical Center At Dallas. "UT Southwestern Researchers Find Lever Involved In Ultrviolet-Ray Sensitivity." ScienceDaily. ScienceDaily, 22 June 1999. <www.sciencedaily.com/releases/1999/06/990622060810.htm>.
University Of Texas Southwestern Medical Center At Dallas. (1999, June 22). UT Southwestern Researchers Find Lever Involved In Ultrviolet-Ray Sensitivity. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/1999/06/990622060810.htm
University Of Texas Southwestern Medical Center At Dallas. "UT Southwestern Researchers Find Lever Involved In Ultrviolet-Ray Sensitivity." ScienceDaily. www.sciencedaily.com/releases/1999/06/990622060810.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC: Get Vaccinated for Measles

CDC: Get Vaccinated for Measles

Reuters - US Online Video (Jan. 30, 2015) The CDC is urging people to get vaccinated for measles amid an outbreak that began at Disneyland and has now infected more than 90 people. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Obama To Outline New Plan For Personalized Medicine

Obama To Outline New Plan For Personalized Medicine

Newsy (Jan. 30, 2015) President Obama is expected to speak with drugmakers Friday about his Precision Medicine Initiative first introduced last week. Video provided by Newsy
Powered by NewsLook.com
NFL Concussions Down; Still on Parents' Minds

NFL Concussions Down; Still on Parents' Minds

AP (Jan. 30, 2015) The NFL announced this week that the number of game concussions dropped by a quarter over last season. Still, the dangers of the sport still weigh on players, and parents&apos; minds. (Jan. 30) Video provided by AP
Powered by NewsLook.com
U.S. Wants to Analyze DNA from 1 Million People

U.S. Wants to Analyze DNA from 1 Million People

Reuters - US Online Video (Jan. 30, 2015) The U.S. has proposed analyzing genetic information from more than 1 million American volunteers to learn how genetic variants affect health and disease. Rough Cut (no reporter narration). Video provided by Reuters
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