Featured Research

from universities, journals, and other organizations

'Vicious Cycle' Of Protein Formation Involved In Parkinson's Disease

Date:
June 30, 2005
Source:
University Of Texas Southwestern Medical Center At Dallas
Summary:
Researchers at UT Southwestern Medical Center have discovered a mechanism that causes a protein to clump together in brain cells of people with Parkinson's disease, pointing toward a possible treatment for the condition.

UT Southwestern's Dr. Chang-Wei Liu (left), research fellow in physiology, Dr. Philip Thomas, professor of physiology, and student research assistant Karen Lewis discovered that a cascade of protein reactions takes place in neurons involved with Parkinson's disease.
Credit: Image courtesy of University Of Texas Southwestern Medical Center At Dallas

DALLAS - June 21, 2005 - Researchers at UT Southwestern Medical Center have discovered a mechanism that causes a protein to clump together in brain cells of people with Parkinson's disease, pointing toward a possible treatment for the condition.

The protein clumping is part of a "vicious cycle," the researchers said. As the proteins cluster, they inhibit an enzyme that normally breaks them down, leading to the formation of even more masses.

"It's a disease involving accumulation of a protein in an aberrant form," said Dr. Philip Thomas, professor of physiology at UT Southwestern and senior author of the study. The research, available online, was published in the June 17 issue of The Journal of Biological Chemistry.

The findings have parallels to other diseases in which protein clusters form in and around nerves, such as Huntington's and Alzheimer's disease.

The culprit in Parkinson's is the protein alpha-synuclein, which normally appears in a long, folded form in cells. It's known to be linked to the disease because mutations in it cause rare, inherited cases of early-onset Parkinson's.

Normally, if a cell becomes stressed, alpha-synuclein unfolds, and an enzyme degrades it completely into harmless bits to prevent the clumping. In Parkinson's patients, however, some of the degrading enzyme malfunctions and creates truncated fragments of alpha-synuclein rather than the harmless bits.

UT Southwestern researchers found that these truncated fragments act like "seeds," encouraging the unfolded form of alpha-synuclein to gather around them. It doesn't take much - just a few molecules of the truncated fragments - to activate this process. Eventually, the cluster is big enough to form a structure called a fibril.

The two forms of the enzyme are usually in balance, with the normal activity outperforming the malicious activity, Dr. Thomas said.

But when the system goes out of balance, the fibrils suppress the normally functioning enzyme, preventing it from fully breaking down the unfolded alpha-synuclein, resulting in even more of the protein being available to form clumps. The clumps also alter the structure of the enzyme in such a way that it produces even more seed fragments. This leads to the formation of more clumps, and so on.

Scientists are still debating which form of the alpha-synuclein protein actually damages the cells, said Dr. Chang-Wei Liu, research fellow in physiology at UT Southwestern and lead author of the study. It could be the mature fibril, or one of the intermediate forms that appears during the degradation process, he said.

Future research may involve uncovering methods to inhibit just the malicious form of the enzyme, while leaving the functions of the normal enzyme unaffected, Dr. Thomas said. Inhibiting only one form is vital, because the normal enzyme is necessary for cells to survive.

Still, the finding reported in The Journal of Biological Chemistry "gives us clues about potential new treatment avenues," he said.

Other UT Southwestern authors of the study are Karen Lewis, student research assistant in physiology, and Dr. George DeMartino, professor of physiology. Researchers at the University of Pennsylvania School of Medicine also contributed.

The work was funded by the National Institutes of Health and the Parkinson's Disease Foundation.


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. "'Vicious Cycle' Of Protein Formation Involved In Parkinson's Disease." ScienceDaily. ScienceDaily, 30 June 2005. <www.sciencedaily.com/releases/2005/06/050630060745.htm>.
University Of Texas Southwestern Medical Center At Dallas. (2005, June 30). 'Vicious Cycle' Of Protein Formation Involved In Parkinson's Disease. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2005/06/050630060745.htm
University Of Texas Southwestern Medical Center At Dallas. "'Vicious Cycle' Of Protein Formation Involved In Parkinson's Disease." ScienceDaily. www.sciencedaily.com/releases/2005/06/050630060745.htm (accessed July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. 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:
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