Welcome to the PrionHome. This is a sequence database that keeps track of the ever-expanding
universe of prions and prion-like phenomena, and their families of related sequences.
For more information, see The PrionHome Project. To download from the database,
go to either Search or Browse. If you wish to contribute your own data, or suggest
changes and improvements, please go to Feedback / Submit Data.
On
the left are various convenient lists of Database entries, grouped
according to 'Organism', 'Prion Name', etc. To access these, please
click on the relevant button.
On the right is a PrionHome news window, where news listings are posted about updates and changes to the database. Particularly useful are the lists of database entries by PrionHome Classification.
There are eight different PrionHome Classifications.The first four are derived from experimental observations. The second four are derived from sequence analysis. The classifications are as follows:
A protein that is known to be form prions. Currently here, we define a prion as any unit of propagation of an altered state of a protein or proteins; the prions are made from an endogenous protein, expressed in the cells of an individual organism; they are either propagated by infection into other individual organisms, or by inheritance to progeny organisms.
If you want a file of prionogenic proteins:
For a file in FASTA format, click here.
For a file in PrionHome Database format, click here. The PrionHome Database format is explained here.
These files comprise all metazoan protein sequences that have been shown to form prions, as well as all of the fungal prionogenic sequences
(including the prionogenic sequences observed in the Alberti, et al. (2009) analysis [Cell (2009); 137:146-58]).
Prionoid: A protein with a prion-like altered state, which demonstrates cell-to-cell propagation, in the absence of evidence for natural organism-to-organism infectivity. Here, we restrict this definition to proteins from multicellular organisms. Some prionoids have demonstrated experimental organism-to-organism propagation.
Other prion-related phenomenon: A protein that has some behaviour like a prion, but does not fit the definition of prion or prionoid.
Interactor: Proteins shown to interact with a prionogenic protein.
Ortholog: An ortholog of a protein that is known to be form prions. Orthologs are the mutually most similar proteins in different organisms. In this database, vertebrate orthologs are also supported by gene synteny in the genomic DNA,
where available.
Paralog: A paralog of a sequence that is known to be form prions. Paralogs are protein/gene duplications within the same genome.
Pseudogene: A copy of a prion-related gene that is formed via retrotransposition, or other processes of duplication, followed by coding-sequence disablement.
Candidate Prionogenic: A protein sequence that contains a candidate prionogenic domain in budding yeast, that has not yet been shown to be prionogenic experimentally. Candidate Prionogenics have two categories:
(i) N/Q-biased: They have domains with an obvious bias for glutamine and/or asparagine residues, with optional contributing biases for glycine, serine and tyrosine, and biases against charged and hydrophobic residues, as observed in the first four described yeast prions. All known amyloid-based prions in budding yeast have regions that have glutamine/asparagine compositional bias.
(ii) Alberti-HMM: They have prion-like composition predicted by the HMM algorithm used in Alberti, et al. (2009) [Cell (2009); 137:146-58], trained on the first four described yeast prion determinants.
This is a rotating sample of images of structures of proteins included in the PrionHome database
