Prion propagates in foreign host

July 05, 2007

Prions -- infectious, oddly-folded proteins that are the main suspects in fatal neurodegenerative diseases such as Cruetzfeldt-Jakob and bovine spongiform encephalopathy, or "mad cow" -- remain mostly a mystery to scientists. Very few prions have been fully described. How they infect and propagate is not fully understood.

New insights into prion propagation reported in the July 6 issue of Molecular Cell by Susan Liebman, distinguished university professor of biological sciences at the University of Illinois at Chicago, may help tug back the veil on the behavior and variety of these potentially lethal molecules.

The work was done with former UIC post-doctoral fellow Vibha Taneja and University of Bordeaux researchers Sven Saupe, Marie-Lise Maddelein and Nicholas Talarek.

Previously, Liebman focused her studies on prion-forming proteins found in baker's yeast, while Saupe's research looked at prion protein in another fungus.

A key difference between the two is that the yeast prion proteins are rich in the amino acids glutamine and asparagine in the regions of the protein used to transform them into a prion. In contrast, the fungal prion lacks a rich supply of these amino acids -- a characteristic it shares with the prion-forming protein in mammals, which is otherwise dissimilar.

The researchers showed, by fusing the prion-forming domain of the fungal protein to a reporter protein, that the fungal prion could propagate in yeast.

"We showed that the fusion formed a prion in yeast and it was infectious," Liebman said. "It's the first time a prion from one organism has been propagated in another organism that normally lacks that prion. It demonstrates that totally heterologous prion propagation is possible.

"Surprisingly, the presence of a glutamine and asparagine-rich yeast prion that helps other yeast prions to form also helped this one to form," Liebman said, showing that prions of one type can interact with a dissimilar type.

Liebman said the finding suggests the possibility that yeast itself may contain non-glutamine and asparagine-rich prions. "We just haven't looked for them," she said.

The finding also underscores the value of the yeast model for studying factors necessary to propagate prions, now that it's been shown that propagation is not necessarily host-specific.

Liebman said the research emphasizes the need to look for new prions.

"How many more are there" Are there lots that we haven't looked at" How do we look for them" These are open questions."
-end-


University of Illinois at Chicago

Related Amino Acids Articles from Brightsurf:

Igniting the synthetic transport of amino acids in living cells
Researchers from ICIQ's Ballester group and IRBBarcelona's Palacín group have published a paper in Chem showing how a synthetic carrier calix[4]pyrrole cavitand can transport amino acids across liposome and cell membranes bringing future therapies a step closer.

Microwaves are useful to combine amino acids with hetero-steroids
Aza-steroids are important class of compounds because of their numerous biological activities.

New study finds two amino acids are the Marie Kondo of molecular liquid phase separation
a team of biologists at the Advanced Science Research Center at The Graduate Center, CUNY (CUNY ASRC) have identified unique roles for the amino acids arginine and lysine in contributing to molecule liquid phase properties and their regulation.

Prediction of protein disorder from amino acid sequence
Structural disorder is vital for proteins' function in diverse biological processes.

A natural amino acid could be a novel treatment for polyglutamine diseases
Researchers from Osaka University, National Center of Neurology and Psychiatry, and Niigata University identified the amino acid arginine as a potential disease-modifying drug for polyglutamine diseases, including familial spinocerebellar ataxia and Huntington disease.

Alzheimer's: Can an amino acid help to restore memories?
Scientists at the Laboratoire des Maladies Neurodégénératives (CNRS/CEA/Université Paris-Saclay) and the Neurocentre Magendie (INSERM/Université de Bordeaux) have just shown that a metabolic pathway plays a determining role in Alzheimer's disease's memory problems.

New study indicates amino acid may be useful in treating ALS
A naturally occurring amino acid is gaining attention as a possible treatment for ALS following a new study published in the Journal of Neuropathology & Experimental Neurology.

Breaking up amino acids with radiation
A new experimental and theoretical study published in EPJ D has shown how the ions formed when electrons collide with one amino acid, glutamine, differ according to the energy of the colliding electrons.

To make amino acids, just add electricity
By finding the right combination of abundantly available starting materials and catalyst, Kyushu University researchers were able to synthesize amino acids with high efficiency through a reaction driven by electricity.

Nanopores can identify the amino acids in proteins, the first step to sequencing
While DNA sequencing is a useful tool for determining what's going on in a cell or a person's body, it only tells part of the story.

Read More: Amino Acids News and Amino Acids Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.