Related Experiment Video

Updated: Apr 20, 2026

High-throughput Screening for Protein-based Inheritance in S. cerevisiae
08:12

High-throughput Screening for Protein-based Inheritance in S. cerevisiae

Published on: August 8, 2017

6.8K

Peptide sequences converting polyglutamine into a prion in yeast

Wataru Odani1, Kazuhiro Urata, Momoko Okuda

  • 1Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.

The FEBS Journal
|November 20, 2014
PubMed

Insights

Amyloid protein aggregates can be transmissible, blurring lines between neurodegenerative diseases. Researchers found specific peptides can convert non-transmissible polyglutamine (polyQ) amyloids into transmissible forms in yeast.

Area of Science:

  • Protein aggregation and prion biology.
  • Molecular mechanisms of protein misfolding and transmission.
  • Yeast as a model organism for studying amyloid dynamics.

Background:

  • Amyloids are ordered protein aggregates with cross-β sheet structures.
  • Prions are infectious amyloids causing transmissible spongiform encephalopathies.
  • The distinction between transmissible and non-transmissible amyloids, like those in Alzheimer's disease, is becoming less clear.

Purpose of the Study:

  • To investigate the dynamics and properties of polyglutamine (polyQ) amyloids in yeast.
  • To understand the mechanism distinguishing transmissible from non-transmissible amyloids.
  • To identify factors that can convert non-transmissible amyloids into transmissible forms.

Main Methods:

  • Utilized yeast cells to study polyglutamine (polyQ) amyloid formation and transmission.
  • Compared the aggregation propensity of polyQ with the yeast prion Sup35.
  • Screened peptides that could convert non-transmissible polyQ aggregates into transmissible ones.
  • Investigated the cellular dynamics of these modified polyQ aggregates.

Main Results:

  • Polyglutamine (polyQ) exhibited a higher tendency to form aggregates than the yeast prion Sup35.
  • Identified specific peptides that, when flanking the polyQ stretch, converted non-transmissible polyQ aggregates into transmissible forms.
  • Observed distinct cellular dynamics associated with the conversion process.

Conclusions:

  • The boundary between transmissible and non-transmissible amyloids is not absolute.
  • Specific molecular interactions, such as flanking peptides, can alter amyloid transmissibility.
  • Yeast models provide a valuable platform for dissecting the mechanisms of amyloid transmission.
Keywords:
Sup35amyloidsfluorescence correlation spectroscopypolyglutamineyeast prions

More Related Videos

Screening for Amyloid Aggregation by Semi-Denaturing Detergent-Agarose Gel Electrophoresis10:03

Screening for Amyloid Aggregation by Semi-Denaturing Detergent-Agarose Gel Electrophoresis

Published on: July 16, 2008

28.8K
Investigating the Spreading and Toxicity of Prion-like Proteins Using the Metazoan Model Organism C. elegans12:57

Investigating the Spreading and Toxicity of Prion-like Proteins Using the Metazoan Model Organism C. elegans

Published on: January 8, 2015

16.8K

Related Concept Videos

Protein Folding Quality Check in the RER01:29

Protein Folding Quality Check in the RER

ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
5.8K
Amyloid Fibrils03:03

Amyloid Fibrils

Amyloid fibrils are aggregates of misfolded proteins.  Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils. 
Amyloid deposits were observed as early as 1639 in the liver and the spleen.   In 1854, Rudolph Virchow performed iodine staining,...
13.2K
Leaky Scanning02:28

Leaky Scanning

During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA.  Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.9K
Signal Sequences and Sorting Receptors01:41

Signal Sequences and Sorting Receptors

Signal sequences are short amino acid sequences that guide newly synthesized proteins to their proper location within the cell. Classical signal sequences are fifteen to sixty amino acids long and present at the N-terminus of a polypeptide chain. Each signal sequence has a conserved segment of basic residues towards their N terminus, a hydrophobic core, and a C-terminus rich in polar residues. The C-terminus also contains a signal cleavage site and features a -3 -1 sequence motif. The -3-1...
15.9K
Proteins: From Genes to Degradation02:11

Proteins: From Genes to Degradation

Within a biological system, the DNA encodes the RNA, and the nucleotide sequence in the RNA further defines the amino acid sequence in the protein. This is referred to as “The Central Dogma of Molecular Biology” - a term coined by Francis Crick.  Central dogma is a firm principle in biology that defines the flow of genetic information within any life form. The two fundamental steps in central dogma are - transcription and translation.
Transcription is the synthesis of RNA...
15.0K
Protein Folding01:25

Protein Folding

Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
12.8K