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P05777 (M1_I33A0) Reviewed, UniProtKB/Swiss-Prot

Last modified October 16, 2013. Version 88. 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:
Matrix protein 1

Short name=M1
Gene names
Name:M
OrganismInfluenza A virus (strain A/Wilson-Smith/1933 H1N1) (Influenza A virus (strain A/WS/1933 H1N1)) [Complete proteome]
Taxonomic identifier381518 [NCBI]
Taxonomic lineageVirusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostAves [TaxID: 8782]
Homo sapiens (Human) [TaxID: 9606]
Sus scrofa (Pig) [TaxID: 9823]

Protein attributes

Sequence length252 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Plays critical roles in virus replication, from virus entry and uncoating to assembly and budding of the virus particle. M1 binding to ribonucleocapsids (RNPs) in nucleus seems to inhibit viral transcription. Interaction of viral NEP with M1-RNP is thought to promote nuclear export of the complex, which is targeted to the virion assembly site at the apical plasma membrane in polarized epithelial cells. Interactions with NA and HA may bring M1, a non-raft-associated protein, into lipid rafts. Forms a continuous shell on the inner side of the lipid bilayer in virion, where it binds the RNP. During virus entry into cell, the M2 ion channel acidifies the internal virion core, inducing M1 dissociation from the RNP. M1-free RNPs are transported to the nucleus, where viral transcription and replication can take place. Ref.7

Determines the virion's shape: spherical or filamentous. Clinical isolates of influenza are characterized by the presence of significant proportion of filamentous virions, whereas after multiple passage on eggs or cell culture, virions have only spherical morphology. Filamentous virions are thought to be important to infect neighboring cells, and spherical virions more suited to spread through aerosol between hosts organisms. Ref.7

Subunit structure

Homodimer and homomultimer. Interacts with NEP By similarity. Binds ribonucleocapsid by both interacting with genomic RNA and NP protein. May interact with HA and NA By similarity. Cannot bind NP without genomic RNA. Ref.5

Subcellular location

Virion membrane; Peripheral membrane protein; Cytoplasmic side. Host nucleus.

Miscellaneous

Most abundant protein in virion. When expressed alone can form virus-like particles in transfected cells.

Sequence similarities

Belongs to the influenza viruses Matrix protein M1 family.

Ontologies

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Note: Only the first 9 residues are shared by the 2 isoforms.
Isoform M1 (identifier: P05777-1)

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 M2 (identifier: P05780-1)

The sequence of this isoform can be found in the external entry P05780.
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 – 252252Matrix protein 1
PRO_0000078868

Regions

Region1 – 164164Membrane-binding
Region165 – 25288RNP-binding
Motif101 – 1055Nuclear localization signal

Experimental info

Mutagenesis411V → A: Induces short filamentous virions. Ref.9
Mutagenesis951K → A or R: No effect. Ref.8 Ref.9
Mutagenesis971V → A: No effect. Ref.8
Mutagenesis981K → A or R: No effect. Ref.8
Mutagenesis991L → A: No effect. Ref.8
Mutagenesis100 – 1034YRKL → AAAA or PPPY: Can't be rescued by reverse genetic. Ref.8
Mutagenesis100 – 1034YRKL → PTAP: No effect. Ref.8
Mutagenesis1001Y → A, F or S: No effect. Ref.8
Mutagenesis101 – 1055RKLKR → SNLNS: 50% loss of RNA binding activity. Ref.4 Ref.8
Mutagenesis101 – 1022RK → PD: No effect. Ref.8
Mutagenesis1011R → A: Reduced growth and small-plaque morphology. Virions have an elongated filamentous morphology. Ref.8
Mutagenesis1011R → K: No effect. Ref.8
Mutagenesis1021K → A or R: No effect. Ref.8
Mutagenesis1031L → A, I or V: No effect. Ref.8
Mutagenesis1041K → A: Can't be rescued by reverse genetic. Ref.8
Mutagenesis1041K → R: No effect. Ref.8
Mutagenesis1051R → A: Can't be rescued by reverse genetic. Ref.8
Mutagenesis1051R → K: Reduced growth and small-plaque morphology. Ref.8
Mutagenesis1061E → A: Can't be rescued by reverse genetic. Ref.8
Mutagenesis1481C → A: No effect. Ref.4 Ref.6
Mutagenesis1481C → S: 31% loss of RNA binding activity. Ref.4 Ref.6
Mutagenesis1511C → A: No effect. Ref.6
Mutagenesis1551A → G: Complete loss of virus ability to be rescued in a reverse genetic system. Ref.6
Mutagenesis1591H → A: No effect. Ref.6
Mutagenesis1621H → A: No effect. Ref.6
Mutagenesis2181T → A: No effect on virion morphology. Ref.9
Sequence conflict1171L → F in AAA43352. Ref.3
Sequence conflict2191I → V in AAA43352. Ref.3
Sequence conflict2311D → S in AAA43252. Ref.2

Sequences

Sequence LengthMass (Da)Tools
Isoform M1 [UniParc].

Last modified July 1, 1989. Version 2.
Checksum: 5F300F18D75BBAD3

FASTA25227,864
        10         20         30         40         50         60 
MSLLTEVETY VLSIVPSGPL KAEIAQRLED VFAGKNTDLE VLMEWLKTRP ILSPLTKGIL 

        70         80         90        100        110        120 
GFVFTLTVPS ERGLQRRRFV QNALNGNGDP NNMDKAVKLY RKLKREITFH GAKEIALSYS 

       130        140        150        160        170        180 
AGALASCMGL IYNRMGAVTT EVAFGLVCAT CEQIADSQHR SHRQMVTTTN PLIRHENRMV 

       190        200        210        220        230        240 
LASTTAKAME QMAGSSEQAA EAMDIASQAR QMVQAMRTIG THPSSSAGLK DDLLENLQAY 

       250 
QKRMGVQMQR FK 

« Hide

Isoform M2 [UniParc].

See P05780.

References

[1]"Nucleotide sequences of influenza A virus RNA segment 7: a comparison of five isolates."
Zebedee S.L., Lamb R.A.
Nucleic Acids Res. 17:2870-2870(1989) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[2]"Nucleotide sequence of RNA segment 7 and the predicted amino sequence of M1 and M2 proteins of FPV/Weybridge (H7N7) and WSN (H1N1) influenza viruses."
Markushin S., Ghiasi H., Sokolov N., Shilov A., Sinitsin B., Brown D., Klimov A., Nayak D.
Virus Res. 10:263-272(1988) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[3]"Transient expression and sequence of the matrix (M1) gene of WSN influenza A virus in a vaccinia vector."
Baylor N.W., Zhiping Y.L., Wagner R.R.
Virology 163:618-621(1988) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[4]"Association of influenza virus matrix protein with ribonucleoproteins."
Ye Z., Liu T., Offringa D.P., McInnis J., Levandowski R.A.
J. Virol. 73:7467-7473(1999) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF 101-ARG--ARG-105 AND CYS-148.
[5]"Influenza virus assembly: effect of influenza virus glycoproteins on the membrane association of M1 protein."
Ali A., Avalos R.T., Ponimaskin E., Nayak D.P.
J. Virol. 74:8709-8719(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: INTERACTION WITH HA AND NA.
[6]"Conserved cysteine and histidine residues in the putative zinc finger motif of the influenza A virus M1 protein are not critical for influenza virus replication."
Hui E.K., Ralston K., Judd A.K., Nayak D.P.
J. Gen. Virol. 84:3105-3113(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF CYS-148; CYS-151; ALA-155; HIS-159 AND HIS-162.
[7]"Reverse genetics studies on the filamentous morphology of influenza A virus."
Bourmakina S.V., Garcia-Sastre A.
J. Gen. Virol. 84:517-527(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[8]"Basic residues of the helix six domain of influenza virus M1 involved in nuclear translocation of M1 can be replaced by PTAP and YPDL late assembly domain motifs."
Hui E.K., Barman S., Yang T.Y., Nayak D.P.
J. Virol. 77:7078-7092(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF LYS-95; VAL-97; LYS-98; LEU-99; TYR-100; ARG-101; LYS-102; LEU-103; LYS-104; ARG-105 AND GLU-106.
[9]"The M1 matrix protein controls the filamentous phenotype of influenza A virus."
Elleman C.J., Barclay W.S.
Virology 321:144-153(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF VAL-41; LYS-95 AND THR-218.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
X08088 Genomic RNA. Translation: CAA30882.1.
M23920 Genomic RNA. Translation: AAA43252.1. Sequence problems.
M19374 Genomic RNA. Translation: AAA43352.1.
L25818 Genomic RNA. Translation: AAA91325.1.
PIRMFIVWS. A28608.
S07429.

3D structure databases

ProteinModelPortalP05777.
SMRP05777. Positions 1-158.
ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D1.10.10.180. 1 hit.
1.20.91.10. 1 hit.
InterProIPR013188. Flu_matrix_M1_C.
IPR001561. Flu_matrix_M1_N.
IPR015423. Flu_matrix_M1_N_sub1.
IPR015799. Flu_matrix_M1_N_sub2.
[Graphical view]
PfamPF00598. Flu_M1. 1 hit.
PF08289. Flu_M1_C. 1 hit.
[Graphical view]
ProDomPD596253. Flu_matrix_M1_C. 1 hit.
PD001061. Flu_matrix_M1_N. 1 hit.
[Graphical view] [Entries sharing at least one domain]
SMARTSM00759. Flu_M1_C. 1 hit.
[Graphical view]
SUPFAMSSF48145. SSF48145. 1 hit.
ProtoNetSearch...

Entry information

Entry nameM1_I33A0
AccessionPrimary (citable) accession number: P05777
Entry history
Integrated into UniProtKB/Swiss-Prot: November 1, 1988
Last sequence update: July 1, 1989
Last modified: October 16, 2013
This is version 88 of the entry and version 2 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