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UniProt release 2014_04

Published April 16, 2014

Headline

An old unwanted guest being shown the door

Poliomyelitis causes disabling paralysis, notably in children and adolescents. It is an old plague. An early case of poliomyelitis is shown on a 3,000-year-old Egyptian stele. The disease is caused by the poliovirus, an RNA virus that colonizes the gastro-intestinal tract without any symptoms. In rare cases, the virus enters the central nervous system, preferentially infecting and destroying motor neurons, leading to muscle weakness and acute flaccid paralysis.

In the late 1940s, John Enders showed that the virus could be grown in cells cultured in vitro. This observation provided the basis for the generation of poliovirus vaccines during the 1950s. Poliomyelitis is now virtually absent in economically developed countries, and the World Health Organization is currently using the vaccine in a far-reaching plan to eradicate the poliovirus worldwide.

Polioviruses are small-sized (30nm), non-enveloped icosahedral viruses composed of a capsid and an 8kb single-stranded RNA genome. Upon entry into a host cell, the poliovirus rearranges cytoplasmic membranes to create double membrane spherical vesicles in which the virus replicates, hidden from the antiviral detectors of the host cell. Once new viral particles are assembled, the host cell undergoes lysis, releasing poliovirus virions.

The poliovirus genome encodes a single polyprotein, which is processed by autocatalytic cleavage into 13 different products that ensure all viral functions from entry and replication to cell exit. The size constraint on the poliovirus genome is enormous, since it has to fit within a 30nm wide capsid. In this context, the polyprotein coding strategy is ideal as it allows the greatest economy of genome length versus protein end products.

In order to reduce redundancy in the knowledgebase, UniProtKB/Swiss-Prot describes all the protein products encoded by one gene in a given species in a single entry. Viral proteins are no exception to the rule. Hence, the poliovirus polyprotein is represented in a single UniProtKB/Swiss-Prot entry, which contains the description of 13 final and 4 intermediate chains.

As of this release, the Genome polyprotein entry of poliovirus type 1 (strain Mahoney) has been updated in UniProtKB/Swiss-Prot.

UniProtKB news

Cross-references for isoform sequences: Ensembl Genomes

We have added isoform-specific cross-references to the Ensembl Genomes sections EnsemblFungi, EnsemblMetazoa, EnsemblPlants and EnsemblProtists. The format of these cross-references is as described in release 2014_03.

Changes to the controlled vocabulary of human diseases

New diseases:

Modified diseases: