Featured Research

from universities, journals, and other organizations

Defective protein is a double hit for ataxia

Date:
April 5, 2010
Source:
Rockefeller University Press
Summary:
The neurodegenerative disease spinocerebellar ataxia type 5 damages nerve cells in two ways. Researchers now report that the defective protein responsible for the disease cuts the number of synaptic terminals and snarls traffic inside neurons.

The neurodegenerative disease spinocerebellar ataxia type 5 (SCA5) damages nerve cells in two ways. University of Minnesota researchers now report that the defective protein responsible for the disease cuts the number of synaptic terminals and snarls traffic inside neurons.

The study appears in the April 5 issue of the Journal of Cell Biology.

SCA5 results from a faulty gene for {beta}-III-spectrin. The disease targets the cerebellum's Purkinje cells, which control coordination. Symptoms usually start when patients are in their 20s or 30s, and they can gradually lose the ability to walk and speak. How the mutant protein damages Purkinje cells remains uncertain. {beta}-III-spectrin stabilizes synapses, suggesting that synapse deterioration might doom the cells. But the protein also helps the adapter protein dynactin hitch cargoes to dynein motors, pointing to a disruption of intracellular transportation.

Lorenzo et al. found support for both mechanisms. They engineered fruit flies to carry a mutated {beta}-III spectrin gene from either of two human families affected with SCA5, including one descended from Abraham Lincoln's paternal grandparents (whether Lincoln himself had the disease isn't clear). Fly larvae with the mutated gene had paralyzed tails. At the neuromuscular junctions where nerves and muscles meet, the larvae showed fewer presynaptic terminals.

The researchers next tracked the movement of synaptic vesicles in axons from the animals. Vesicles from flies that made the faulty {beta}-III-spectrin were slower and more likely to change direction, and thus traveled shorter distances. Other neurodegenerative diseases, including Alzheimer's disease and amyotrophic lateral sclerosis, involve faulty transport, and the results indicate that SCA5 does too.

The two mechanisms might have a common link, the researchers suggest. The complex containing {beta}-III-spectrin, dynactin, and dynein might not just haul cargoes. At the synapse it might snag microtubules that strengthen the membrane and prevent degeneration.


Story Source:

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


Journal Reference:

  1. D. N. Lorenzo, M. g. Li, S. E. Mische, K. R. Armbrust, L. P. W. Ranum, T. S. Hays. Spectrin mutations that cause spinocerebellar ataxia type 5 impair axonal transport and induce neurodegeneration in Drosophila. The Journal of Cell Biology, 2010; 189 (1): 143 DOI: 10.1083/jcb.200905158

Cite This Page:

Rockefeller University Press. "Defective protein is a double hit for ataxia." ScienceDaily. ScienceDaily, 5 April 2010. <www.sciencedaily.com/releases/2010/04/100405091924.htm>.
Rockefeller University Press. (2010, April 5). Defective protein is a double hit for ataxia. ScienceDaily. Retrieved April 21, 2014 from www.sciencedaily.com/releases/2010/04/100405091924.htm
Rockefeller University Press. "Defective protein is a double hit for ataxia." ScienceDaily. www.sciencedaily.com/releases/2010/04/100405091924.htm (accessed April 21, 2014).

Share This



More Mind & Brain News

Monday, April 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Study On Artists' Brain Shows They're 'Structurally Unique'

Study On Artists' Brain Shows They're 'Structurally Unique'

Newsy (Apr. 17, 2014) The brains of artists aren't really left-brain or right-brain, but rather have extra neural matter in visual and motor control areas. Video provided by Newsy
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Are School Dress Codes Too Strict?

Are School Dress Codes Too Strict?

AP (Apr. 16, 2014) Pushing the limits on style and self-expression is a rite of passage for teens and even younger kids. How far should schools go with their dress codes? The courts have sided with schools in an era when school safety is paramount. (April 16) Video provided by AP
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. 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