User:Claire Roudot/Sandbox 1
From Proteopedia
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| - | This fungus lives in genetically compatible colonies and share cellular contents such as nutriments and cytoplasm. A natural system of proteins helps incompatibility protection and prevent promiscuous between different colonies. The protein HET-S is one of them and it adopts a prion-like form in order to function properly. [1] The prion form of HET-S spreads rapidly throughout the cellular network of a colony and can convert the non-prion form of the protein to a prion state after compatible colonies have merged.[2] However, when an incompatible colony tries to merge with a prion-containing colony, the prion causes the "invader" cells to die, ensuring that only related colonies obtain the benefit of sharing resources. | + | This fungus lives in genetically compatible colonies and share cellular contents such as nutriments and cytoplasm. A natural system of proteins helps incompatibility protection and prevent promiscuous between different colonies. The protein HET-S is one of them and it adopts a prion-like form in order to function properly. <ref>[1] The prion form of HET-S spreads rapidly throughout the cellular network of a colony and can convert the non-prion form of the protein to a prion state after compatible colonies have merged.[2] However, when an incompatible colony tries to merge with a prion-containing colony, the prion causes the "invader" cells to die, ensuring that only related colonies obtain the benefit of sharing resources. |
It means that the prion form of HET-s plays a role in heterokaryon incompatibility, a fungal self/nonself recognition phenomenon that prevents different form of parasitism. | It means that the prion form of HET-s plays a role in heterokaryon incompatibility, a fungal self/nonself recognition phenomenon that prevents different form of parasitism. | ||
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== References == | == References == | ||
| - | [1] Paushkin, S. V., V. V. Kushnirov, V. N. Smirnov and M. D. Ter-Avanesyan (1996). "Propagation of the yeast prion-like PSI+ determinant is mediated by oligomerization of the SUP35-encoded polypeptide chain release factor". EMBO (European Molecular Biology Organization) Journal 15, 3127–3134 | + | <ref> [1] Paushkin, S. V., V. V. Kushnirov, V. N. Smirnov and M. D. Ter-Avanesyan (1996). "Propagation of the yeast prion-like PSI+ determinant is mediated by oligomerization of the SUP35-encoded polypeptide chain release factor". EMBO (European Molecular Biology Organization) Journal 15, 3127–3134 </ref> |
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[2] Shewmaker F, Wickner RB and Tycko R, Proc Natl Acad Sci U S A. 2006 Dec 26;103(52):19754-9. | [2] Shewmaker F, Wickner RB and Tycko R, Proc Natl Acad Sci U S A. 2006 Dec 26;103(52):19754-9. | ||
Revision as of 16:10, 19 November 2009
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Amyloid Fibrils of the HET-s(218-289) Prion Form
The HET- protein from the filamentous fungus Podospora Anserina has a prion forming domain from residues 218 to 289.
Prions are proteins Prp-sc and they can get an unasual withdrawal, whose can been transmit to the natural protein Prp-c.
Prions are often implicated in disease such as Creutzeld Jakob disease in humans, it can be also found in yeast and filamentous fungi (in this case it is harmless).
The prion proteins of fungus in their infectious form makes some fibrillar structures which are very hardy and are called amyloid fibrils. This amyloid fribrils are protein structures taht is also found in a human neurodegenarative diseases as Parkinson disease or Alzheimer disesase.
This fungus lives in genetically compatible colonies and share cellular contents such as nutriments and cytoplasm. A natural system of proteins helps incompatibility protection and prevent promiscuous between different colonies. The protein HET-S is one of them and it adopts a prion-like form in order to function properly. [1]
[2] Shewmaker F, Wickner RB and Tycko R, Proc Natl Acad Sci U S A. 2006 Dec 26;103(52):19754-9.
Wasmer C, Lange A, Van Melckebeke H, Siemer AB, Riek R, Meier BH. Amyloid fibrils of the HET-s(218-289) prion form a beta solenoid with a triangular hydrophobic core. Science. 2008 Mar 14;319(5869):1523-6[1]. PMID:18339938
Text of CNRS [2]
