Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers discover protein that dissolves amyloid fibers

21.05.2004


Amyloid fibers, those clumps of plaque-like proteins that clog up the brains of Alzheimer’s patients, have perplexed scientists with their robust structures. In laboratory experiments, they are able to withstand extreme heat and cold and powerful detergents that cripple most other proteins. The fibers are in fact so tough that researchers now are exploring ways that they can be used in nanoscale industrial applications. While they are not necessarily the cause of Alzheimer’s, they are associated with it and with many other neurological conditions, and researchers don’t yet have a way to assail these resilient molecules.



A study published this week in the advance online publication of the journal Science suggests that yeast may succeed where scientists have not. The research by a team at Whitehead Institute for Biomedical Research reports on a natural biological process by which yeast cells dismantle amyloid fibers.

"These proteins are remarkably stable," says Susan Lindquist, director of Whitehead and lead researcher on the project. "This is the first time that anyone has found anything that can catalytically take apart an amyloid fiber."


The finding follows years of study that has focused on a yeast protein called Sup35, a protein that helps cells translate genetic information into strings of amino acids – the building blocks of protein molecules. Sometimes Sup35 suddenly forms amyloid fibers similar to those found in Alzheimer’s patients. In yeast, however, this doesn’t kill the cell. Rather, it is part of the cell’s normal biology, changing the types of proteins that the cell makes – changes that can sometimes be beneficial.

Previous research in the Lindquist lab described how a protein called Hsp104 seemed to affect Sup35’s ability to form amyloid fibers. When a yeast cell contained either high amounts of Hsp104 or none at all, amyloid fibers never formed. But when Hsp104 levels were small, the fibers flourished.

While these types of relationships between chemicals aren’t unheard of, "it was counter-intuitive. Both high levels of Hsp104 and the absence of Hsp104 caused the same effect. That certainly made us want to figure out what was going on," says Lindquist, who is also a professor of biology at MIT. "It was hard to come up with a definitive experiment in a living cell that would explain this sort of thing."

In this new study, Lindquist and postdoctoral researcher James Shorter isolated Sup35 and Hsp104. Here they saw that small amounts of Hsp104 catalyzed the formation of amyloid fibers, but large levels of the protein actually caused the fibers to dissolve.

"Given their resilient structure, the fact that a protein can take apart these amyloids is remarkable," says Lindquist. "It has huge implications for our understanding of the protein folding process in amyloid-related conditions."

This research also may contribute to scientists’ understanding of evolution. Prions, those infectious proteins implicated in conditions such as mad cow disease, are a subclass of amyloids. In yeast cells, Sup35 technically is a prion, although it is not toxic to the cell. Many researchers suspect that because prions have been so well conserved in yeast for hundreds of thousands of years, they must serve some sort of evolutionary purpose – and that’s where Hsp104 comes in.

Hsp104 belongs to a class of proteins that sometimes are influenced by environmental factors. It is conceivable, Shorter explains, that a yeast cell in one type of environment can experience an abundance of Hsp104, which would then keep Sup35 from forming amyloid fibers in that cell. But put that cell in a different environment and the result may be a more moderate level of Hsp104 that would, in turn, create amyloid fibers in Sup35, changing how that protein functions and ultimately altering the cell’s biology. And because these changes could then be passed on to subsequent generations of cells, this, the scientists note, would be an example of environment guiding the evolutionary process.

"This is speculation that hasn’t been demonstrated yet," says Shorter. "For obvious reasons it’s hard to prove any evolutionary argument. But this paper is one indication that this might be the case."

David Cameron | EurekAlert!
Further information:
http://www.wi.mit.edu/home.html

More articles from Life Sciences:

nachricht Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>