Navigation Links
Zinc, proteins, and an essential cellular balancing act
Date:9/30/2013

MADISON Scientists at the University of Wisconsin-Madison have made a discovery that, if replicated in humans, suggests a shortage of zinc may contribute to diseases like Alzheimer's and Parkinson's, which have been linked to defective proteins clumping together in the brain.

With proteins, shape is everything. The correct shape allows some proteins to ferry atoms or molecules about a cell, others to provide essential cellular scaffolding or identify invading bacteria for attack. When proteins lose their shape due to high temperature or chemical damage, they stop working and can clump together a hallmark of Parkinson's and Alzheimer's.

The UW researchers have discovered another stress that decreases protein stability and causes clumping: a shortage of zinc, an essential metal nutrient.

Zinc ions play a key role in creating and holding proteins in the correct shape. In a study just published in the online Journal of Biological Chemistry, Colin MacDiarmid and David Eide show that the gene Tsa1 creates "protein chaperones" that prevent clumping of proteins in cells with a zinc shortage. By holding proteins in solution, Tsa1 prevents damage that can otherwise lead to cell death.

For simplicity, the researchers studied the system in yeast a single-celled fungus. Yeast can adapt to both shortages and excesses of zinc, says MacDiarmid, an associate scientist. "Zinc is an essential nutrient but if there's too much, it's toxic. The issue for the cell is to find enough zinc to grow and support all its functions, while at the same time not accumulating so much that it kills the cell."

Cells that are low in zinc also produce proteins that counter the resulting stress, including one called Tsa1.

The researchers already knew that Tsa1 could reduce the level of harmful oxidants in cells that are short of zinc. Tsa1, MacDiarmid says, "is really a two-part protein. It can get rid of dangerous reactive oxygen species that damage proteins, but it also has this totally distinct chaperone function that protects proteins from aggregating. We found that the chaperone function was the more important of the two."

"In yeast, if a cell is deficient in zinc, the proteins can mis-fold, and Tsa1 is needed to keep the proteins intact so they can function," says Eide, a professor of nutritional science. "If you don't have zinc, and you don't have Tsa1, the proteins will glom together into big aggregations that are either toxic by themselves, or toxic because the proteins are not doing what they are supposed to do. Either way, you end up killing the cell."

While the medical implications remain to be explored, there are clear similarities between yeast and human cells. "Zinc is needed by all cells, all organisms, it's not just for steel roofs, nails and trashcans," Eide says. "The global extent of zinc deficiency is debated, but diets that are high in whole grains and low in meat could lead to deficiency."

If low zinc supply has the same effect on human cells as on yeast, zinc deficiency might contribute to human diseases that are associated with a build-up of "junked" proteins, such as Parkinson's and Alzheimer's. Eide says a similar protective system to Tsa1 also exists in animals, and the research group plans to move ahead by studying that system in human cell culture.


'/>"/>

Contact: Colin MacDiarmid
macdiarmid@nutrisci.wisc.edu
608-262-1118
University of Wisconsin-Madison
Source:Eurekalert

Related biology news :

1. Immune system fighters speak in patterns of proteins, prefer squishy partners
2. Juniper essential oil characteristics determined
3. Protein targeted for cancer drug development is essential for normal heart function
4. Animated Essential Atlas of Anatomoy and Physiology Anatomy Atlas
5. Breakthrough research of essential molecule reveals important targets in diabetes and obesity
6. CNIO researchers identify a new gene that is essential for nuclear reprogramming
7. Study points to essential role of IL-22 in lung repair after the flu
8. Sex and gender competency essential to medical care
9. Essential informatics methods and tools for analyzing the explosion of NGS data
10. Scientists discover structure of protein essential for quality control, nerve function
11. Nature study reveals loss of essential blood cell gene leads to anemia
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/20/2016)... DALLAS , June 20, 2016 ... criminal justice technology solutions for public safety, investigation, ... by the prisons involved, it has secured the ... Corrections (DOC) facilities for Managed Access Systems (MAS) ... (4) additional facilities to be installed by October, ...
(Date:6/9/2016)... 2016 Paris Police Prefecture ... security solution to ensure the safety of people and operations ... the major tournament Teleste, an international technology group ... announced today that its video security solution will be utilised ... up public safety across the country. The system roll-out is ...
(Date:6/2/2016)... YORK , June 2, 2016   The Weather ... is announcing Watson Ads, an industry-first capability in which consumers ... by being able to ask questions via voice or text ... Marketers have long sought ... the consumer, that can be personal, relevant and valuable; and ...
Breaking Biology News(10 mins):
(Date:12/5/2016)... LAKE, N.J. , Dec. 5, 2016 /PRNewswire/ ... Phase 3 open-label two-year study of rufinamide, which ... the American Epilepsy Society (AES) held from December ... Analysis of final two-year safety, tolerability and cognitive ... with rufinamide experienced similar safety and tolerability profiles, ...
(Date:12/4/2016)...  In five studies being presented today during the ... Exposition in San Diego , researchers ... delivery of life-saving treatments to patients with a variety ... carry therapies directly to the sites in the body ... substantial advantage over traditional, systemic methods. The studies highlight ...
(Date:12/2/2016)... OAKS, Calif. , Dec. 2, 2016 Amgen ... AGN ) today announced the submission of a Marketing ... ABP 215, a biosimilar candidate to Avastin ® (bevacizumab). ... application submitted to the EMA. "The submission ... as Amgen seeks to expand our oncology portfolio," said ...
(Date:12/2/2016)... ... December 01, 2016 , ... Aerocom Healthcare ( ... hospitals, will present its chain-of-custody solution for tracking and securing medications at booth ... Dec. 4-8, 2016. , Aerocom has a proven solution for tracking medications via ...
Breaking Biology Technology: