Related Experiment Video
Updated: Jun 5, 2026
09:43
Purification and Refolding to Amyloid Fibrils of (His)6-tagged Recombinant Shadoo Protein Expressed as Inclusion Bodies in E. coli
Published on: December 19, 2015
Conserved stress-protective activity between prion protein and Shadoo
Vignesh Sakthivelu1, Ralf P Seidel, Konstanze F Winklhofer
1Neurobiochemistry, Adolf-Butenandt-Institute, Ludwig-Maximilians-University Munich, D-80336 Munich, Germany.
The Journal of Biological Chemistry
|January 25, 2011
Summary
Shadoo (Sho) and cellular prion protein (PrP(C)) share stress-protective functions, particularly involving their N-terminal domains. Both proteins utilize similar pathways to shield cells from excitotoxicity and other physiological stressors.
Area of Science:
- Neurobiology
- Molecular Biology
- Cellular Stress Response
Background:
- Shadoo (Sho) is a neuronally expressed glycoprotein with an unknown function.
- Sho shares structural similarities with the cellular prion protein (PrP(C)), including a hydrophobic domain (HD) and glycosylphosphatidylinositol (GPI) anchor.
- Previous research indicated Sho can mitigate the toxicity of a PrP mutant lacking the HD (PrPΔHD).
Purpose of the Study:
- To investigate the stress-protective activity of Sho and identify its functional domains.
- To compare the functional roles of Sho and PrP(C) in cellular stress protection.
- To explore the potential for functional replacement between the N-terminal domains of Sho and PrP(C).
Main Methods:
- Comparative analysis of Sho and PrP(C) protein domains (N-terminal, HD) in stress protection assays.
- Assessment of cellular protection against excitotoxicity (e.g., glutamate) and other physiological stressors.
- Investigation of protein homodimerization mediated by the HD.
- Functional domain-swapping experiments between Sho and PrP(C) N-termini.
Main Results:
- Sho, like PrP(C), protects cells against physiological stressors such as glutamate.
- The N-terminal domain of both Sho and PrP(C) is crucial for their stress-protective activity; deletions (ShoΔN, PrPΔN) significantly impaired this function.
- The HD promotes homodimer formation in both proteins, but domain deletions had differential effects: ShoΔHD lost protection, while PrPΔHD became neurotoxic.
- The N-terminal domain of PrP(C) could be functionally substituted by that of Sho, indicating conserved function.
Conclusions:
- Sho and PrP(C) exhibit conserved physiological activity in protecting cells from stress-induced toxicity.
- Both proteins rely on their N-terminal domains for stress-protective functions.
- Sho and PrP(C) likely operate through similar signaling pathways to mediate cellular protection.
Related Concept Videos
01:30Other Stress Responses in Bacteria
Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
03:03Amyloid 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, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
02:26Conservation of Protein Domains
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
02:26Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
01:26Bacterial Protein Maturation
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
03:00Molecular Chaperones and Protein Folding
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...