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O56264 (NS1_I97A1) Reviewed, UniProtKB/Swiss-Prot

Last modified July 9, 2014. Version 71. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Alt products·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Non-structural protein 1

Short name=NS1
Alternative name(s):
NS1A
Gene names
Name:NS
OrganismInfluenza A virus (strain A/Hong Kong/156/1997 H5N1 genotype Gs/Gd) [Complete proteome]
Taxonomic identifier130763 [NCBI]
Taxonomic lineageVirusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostAves [TaxID: 8782]
Felis catus (Cat) (Felis silvestris catus) [TaxID: 9685]
Homo sapiens (Human) [TaxID: 9606]
Panthera pardus (Leopard) (Felis pardus) [TaxID: 9691]
Panthera tigris (Tiger) [TaxID: 9694]
Sus scrofa (Pig) [TaxID: 9823]

Protein attributes

Sequence length230 AA.
Sequence statusComplete.
Protein existenceInferred from homology

General annotation (Comments)

Function

Inhibits post-transcriptional processing of cellular pre-mRNA, by binding and inhibiting two cellular proteins that are required for the 3'-end processing of cellular pre-mRNAs: the 30 kDa cleavage and polyadenylation specificity factor (CPSF4) and the poly(A)-binding protein 2 (PABPN1). This results in the accumulation of unprocessed 3' end pre-mRNAs which can't be exported from the nucleus. Cellular protein synthesis is thereby shut off very early after virus infection. Viral protein synthesis is not affected by the inhibition of the cellular 3' end processing machinery because the poly(A) tails of viral mRNAs are produced by the viral polymerase through a stuttering mechanism By similarity.

Prevents the establishment of the cellular antiviral state by inhibiting TRIM25-mediated DDX58 ubiquitination, which normally triggers the antiviral transduction signal that leads to the activation of type I IFN genes by transcription factors like IRF3 and IRF7. Prevents human EIF2AK2/PKR activation, either by binding double-strand RNA, or by interacting directly with EIF2AK2/PKR. This function may be important at the very beginning of the infection, when NS1 is mainly present in the cytoplasm. Also binds poly(A) and U6 snRNA. Suppresses the RNA silencing-based antiviral response in Drosophila cells By similarity.

Subunit structure

Homodimer. Interacts with host TRIM25 (via coiled coil); this interaction specifically inhibits TRIM25 multimerization and TRIM25-mediated DDX58 CARD ubiquitination. Interacts with human EIF2AK2/PKR, CPSF4, IVNS1ABP and PABPN1 By similarity.

Subcellular location

Host nucleus. Host cytoplasm. Note: In uninfected, transfected cells, NS1 is localized in the nucleus. Only in virus infected cells, the nuclear export signal is unveiled, presumably by a viral protein, and a fraction of NS1 is exported in the cytoplasm.

Domain

The dsRNA-binding region is required for suppression of RNA silencing By similarity.

Sequence similarities

Belongs to the influenza A viruses NS1 family.

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]
Isoform NS1 (identifier: O56264-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
Isoform NEP (identifier: O56263-1)

Also known as: NS2;

The sequence of this isoform can be found in the external entry O56263.
Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 230230Non-structural protein 1
PRO_0000078931

Regions

Region1 – 7373RNA-binding By similarity
Region180 – 21536CPSF4-binding By similarity
Region223 – 2308PABPN1-binding By similarity
Motif34 – 385Nuclear localization signal 1 By similarity
Motif137 – 14610Nuclear export signal By similarity
Motif216 – 2216Nuclear localization signal 2 By similarity

Sequences

Sequence LengthMass (Da)Tools
Isoform NS1 [UniParc].

Last modified June 1, 1998. Version 1.
Checksum: E0CA9F181FC60A51

FASTA23026,237
        10         20         30         40         50         60 
MDSNTVSSFQ VDCFLWHVRK RFADQELGDA PFLDRLRRDQ KSLRGRGSTL GLDIRTATRE 

        70         80         90        100        110        120 
GKHIVERILE EESDEALKMT IASVPAPRYL TEMTLEEMSR DWLMLIPKQK VTGSLCIRMD 

       130        140        150        160        170        180 
QAIMDKDIIL KANFSVIFNR LEALILLRAF TDEGAIVGEI SPLPSLPGHT EEDVKNAIGV 

       190        200        210        220        230 
LIGGLEWNDN TVRVSETLQR FTWRSSDENG RSPLPPKQKR KMERTIEPEV 

« Hide

Isoform NEP (NS2) [UniParc].

See O56263.

References

[1]"Characterization of an avian influenza A (H5N1) virus isolated from a child with a fatal respiratory illness."
Subbarao K., Klimov A., Katz J., Regnery H., Lim W., Hall H., Perdue M., Swayne D., Bender C., Huang J., Hemphill M., Rowe T., Shaw M., Xu X., Fukuda K., Cox N.
Science 279:393-396(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[2]"Avian-to-human transmission of H9N2 subtype influenza A viruses: relationship between H9N2 and H5N1 human isolates."
Lin Y.P., Shaw M., Gregory V., Cameron K., Lim W., Klimov A., Subbarao K., Guan Y., Krauss S., Shortridge K., Webster R., Cox N., Hay A.
Proc. Natl. Acad. Sci. U.S.A. 97:9654-9658(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
Strain: A/Hong Kong/1074/99.
[3]"Comparisons of highly virulent H5N1 influenza A viruses isolated from humans and chickens from Hong Kong."
Suarez D.L., Perdue M.L., Cox N., Rowe T., Bender C., Huang J., Swayne D.E.
J. Virol. 72:6678-6688(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[4]"Intracellular warfare between human influenza viruses and human cells: the roles of the viral NS1 protein."
Krug R.M., Yuan W., Noah D.L., Latham A.G.
Virology 309:181-189(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: REVIEW.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AF036360 Genomic RNA. Translation: AAC34268.1.
AJ404736 Genomic RNA. Translation: CAC04091.1.
AF046091 Genomic RNA. Translation: AAC32092.1.

3D structure databases

ProteinModelPortalO56264.
SMRO56264. Positions 1-72, 79-205.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

IntActO56264. 108 interactions.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D1.10.287.10. 1 hit.
InterProIPR000256. Flu_NS1.
IPR009068. S15_NS1_RNA-bd.
[Graphical view]
PfamPF00600. Flu_NS1. 1 hit.
[Graphical view]
SUPFAMSSF47060. SSF47060. 1 hit.
ProtoNetSearch...

Entry information

Entry nameNS1_I97A1
AccessionPrimary (citable) accession number: O56264
Secondary accession number(s): Q77XR5
Entry history
Integrated into UniProtKB/Swiss-Prot: December 6, 2005
Last sequence update: June 1, 1998
Last modified: July 9, 2014
This is version 71 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families