Featured Research

from universities, journals, and other organizations

Artificial Prions Created

Date:
March 23, 2004
Source:
Public Library Of Science
Summary:
Researchers have identified the amino acid sequences that allow prions to aggregate and replicate - and thereby pass through generations of cells - and prove this by designing an artificial yeast prion that does not exist in nature.

The culprit behind mad cow disease, a.k.a. bovine spongiform encephalopathy, is the most infamous mammalian form of prions. Prions are misfolded proteins that are capable of growing, replicating, and being passed on to daughter cells - that is, they are by themselves heritable. Beyond their disease manifestation, prions also occur naturally in some organisms (such as yeast) and may play important roles in their growth and development. Now, Osherovich and colleagues have identified the amino acid sequences that allow prions to aggregate and replicate - and thereby pass through generations of cells - and prove this by designing an artificial yeast prion that does not exist in nature.

Prion-forming proteins normally exist as normal cellular components. But they possess the innate ability to alter their three-dimensional structure, which changes their function and makes them almost impossible to destroy. Prions grow by inducing normal proteins to alter their shape and adhere to an initial aggregate "seed." These growing masses are then thought to divide with the help of "chaperones," cellular proteins that aid in protein folding and transport, resulting in smaller prion particles called propagons. The propagons are then distributed to both mother and daughter cells during division, thereby infecting the next generation of cells.

Lev Osherovich and colleagues confirmed what others have seen, namely that an area rich in glutamine and asparagine was responsible for the aggregation and growth of prions-acting like a patch of Velcro that locks the misshapen proteins together. They went on to find that a short stretch of peptide repeats was required for the inheritance of prions - the proper division of prion masses and subsequent distribution of propagons during cell division. The authors suggest that oligopeptide repeats function as a secure binding location for chaperone proteins, which are necessary for heritability, and thus infectiousness, of prions. These results help explain why stable inheritance of prions is rare; while many proteins have stretches of amino acids similar to the aggregation sequence, few also contain sequences that permit inheritance. Osherovich and colleagues were able to create an artificial prion by fusing the oligopeptide repeats to an expanded polyglutamine tract.

By creating artificial hybrid prions, Osherovich and colleagues showed that the two discrete elements of prion-forming domains are portable and work together regardless of their origins. The authors suggest that other artificial prions could be used as a model system to study different types of aggregation sequences, such as those found in the human prion protein responsible for Creutzfeldt-Jakob's disease or the misshapen plaques of proteins that contribute to Alzheimer's disease.

###

citation: Osherovich LZ, Cox BS, Tuite MF, Weissman JS (2004) Dissection and design of yeast prions. PLoS Biol: e86 DOI: 10.1371/journal.pbio.0020086

link (available on date of publication): http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0020086


Story Source:

The above story is based on materials provided by Public Library Of Science. Note: Materials may be edited for content and length.


Cite This Page:

Public Library Of Science. "Artificial Prions Created." ScienceDaily. ScienceDaily, 23 March 2004. <www.sciencedaily.com/releases/2004/03/040323070139.htm>.
Public Library Of Science. (2004, March 23). Artificial Prions Created. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2004/03/040323070139.htm
Public Library Of Science. "Artificial Prions Created." ScienceDaily. www.sciencedaily.com/releases/2004/03/040323070139.htm (accessed August 1, 2014).

Share This




More Plants & Animals News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
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
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) 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:
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