Featured Research

from universities, journals, and other organizations

Getting to the root of Parkinson's disease

Date:
April 10, 2014
Source:
Johns Hopkins Medicine
Summary:
Working with human neurons and fruit flies, researchers have identified and then shut down a biological process that appears to trigger a particular form of Parkinson’s disease present in a large number of patients. The new research builds on a growing body of knowledge about the origins of Parkinson's disease, whose symptoms appear when dopamine-producing nerve cells in the brain degenerate.

Working with human neurons and fruit flies, researchers at Johns Hopkins have identified and then shut down a biological process that appears to trigger a particular form of Parkinson's disease present in a large number of patients. A report on the study, in the April 10 issue of the journal Cell, could lead to new treatments for this disorder.

"Drugs such as L-dopa can, for a time, manage symptoms of Parkinson's disease, but as the disease worsens, tremors give way to immobility and, in some cases, to dementia. Even with good treatment, the disease marches on," says Ted Dawson, M.D., Ph.D., professor of neurology and director of the Johns Hopkins Institute for Cell Engineering,

Dawson says the new research builds on a growing body of knowledge about the origins of Parkinson's disease, whose symptoms appear when dopamine-producing nerve cells in the brain degenerate. Further evidence for a role of genetics in Parkinson's disease appeared a decade ago when researchers identified key mutations in an enzyme known as leucine-rich repeat kinase 2, or LRRK2 -- pronounced "lark2." When that enzyme was cloned, Dawson, together with his wife and longtime collaborator Valina Dawson, Ph.D., professor of neurology and member of the Institute for Cell Engineering, discovered that LRRK2 was a kinase, a type of enzyme that transfers phosphate groups to proteins and turns proteins on or off to change their activity.

Over the years, it was found that blocking kinase activity in mutated LRRK2 halted degeneration, while enhancing it made things worse. But nobody knew what proteins LRRK2 was acting on.

"For nearly a decade, scientists have been trying to figure out how mutations in LRRK2 cause Parkinson's disease," said Margaret Sutherland, Ph.D., a program director at the National Institute of Neurological Disorders and Stroke. "This study represents a clear link between LRRK2 and a pathogenic mechanism linked to Parkinson's disease."

Dawson went fishing for the right proteins using LRRK2 as bait. When his team began to identify those proteins, Dawson says they were surprised to discover that many were linked to the cellular machinery, like ribosomes, that make proteins. Nobody, says Dawson, suspected that LRRK2 might be involved at such a basic level as protein manufacture.

Unsure if they were right, the team then tested the proteins they identified to see which of them, if any, LRRK2 could add phosphate groups to. They came up with three ribosomal protein candidates -- s11, s15 and s27. They then altered each ribosomal protein to see what would happen. It turned out that mutating s15 in a manner that blocked LRRK2 phosphorylation protected nerve cells taken from rats, humans and fruit flies from death. In other words, s15 appeared to be the much sought-after target of LRRK2, Dawson says.

"When you go fishing, you want to catch fish. We just happened to catch a big one," Dawson says.

With the protein now identified, Dawson's team is tackling further experiments to find out how excess protein production causes dopamine neurons to degenerate. And they want to see what happens when they block LRRK2 from phosphorylating the s15 protein in mice, to build on their findings from fruit flies and nerve cells grown in a dish.

"There's a big chasm between animal disease models and human treatments," says Ian Martin, Ph.D., a neuroscientist in Dawson's lab and the lead author on the paper. "But it's exciting. I think it definitely could turn into something real, hopefully in my lifetime."


Story Source:

The above story is based on materials provided by Johns Hopkins Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ian Martin, JungwooWren Kim, ByoungDae Lee, HoChul Kang, Jin-Chong Xu, Hao Jia, Jeannette Stankowski, Min-Sik Kim, Jun Zhong, Manoj Kumar, ShaidaA. Andrabi, Yulan Xiong, DennisW. Dickson, ZbigniewK. Wszolek, Akhilesh Pandey, TedM. Dawson, ValinaL. Dawson. Ribosomal Protein s15 Phosphorylation Mediates LRRK2 Neurodegeneration in Parkinson’s Disease. Cell, 2014; 157 (2): 472 DOI: 10.1016/j.cell.2014.01.064

Cite This Page:

Johns Hopkins Medicine. "Getting to the root of Parkinson's disease." ScienceDaily. ScienceDaily, 10 April 2014. <www.sciencedaily.com/releases/2014/04/140410121935.htm>.
Johns Hopkins Medicine. (2014, April 10). Getting to the root of Parkinson's disease. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/2014/04/140410121935.htm
Johns Hopkins Medicine. "Getting to the root of Parkinson's disease." ScienceDaily. www.sciencedaily.com/releases/2014/04/140410121935.htm (accessed September 3, 2014).

Share This



More Health & Medicine News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Doctors Fear They're Losing Battle Against Ebola

Doctors Fear They're Losing Battle Against Ebola

AP (Sep. 2, 2014) As a third American missionary is confirmed to have contracted Ebola in Liberia, doctors on the ground in West Africa fear they're losing the battle against the outbreak. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Tech Giants Bet on 3D Headsets for Gaming, Healthcare

Tech Giants Bet on 3D Headsets for Gaming, Healthcare

AFP (Sep. 2, 2014) When Facebook acquired the virtual reality hardware developer Oculus VR in March for $2 billion, CEO Mark Zuckerberg hailed the firm's technology as "a new communication platform." Duration: 02:24 Video provided by AFP
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