H5N1 subtype

VIRION

Molecular biology

Enveloped. Usually rounded but can be filamentous. The virions are 80-120 nm in diameter.

GENOME

Segmented ssRNA(-) linear genome, encapsidated by nucleoprotein (NP). Contains 8 segments coding for 12-13 proteins depending on strains. Segments size range from 890 to 2,341nt. Genome total size is 13.5Kb

GENE EXPRESSION

Viral RNA polymerase (PB1, PB2 and PA) transcribes one mRNA from each genome segment. Transcription is primed by cap cleaved from cellular mRNAS by Cap snatching. mRNA are polyadenylated by the viral polymerase stuttering on a poly U track MP and NS mRNA can be alternately spliced, giving rise to mRNA coding for M2 and NEP proteins. PB1 mRNA encode three proteins by leaky scanning: PB1, N40 and PB1-F2 . Pa-X protein is translated by ribosomal frameshift on the PA gene .

REPLICATION

NUCLEUS

  1. Virus attaches to sialic acid receptor though HA protein and is endocytosed by clathrins in the host cell.
  2. endosome acidification induces fusion of virus membrane with the vesicle membrane; encapsidated RNA segments migrate to the nucleus.
  3. Transcription of genomic segments by the viral polymerase produces mRNAs that are capped and polyadenylated by the viral polymerase.
  4. Replication of genomic segments.
  5. High level of M1 protein induces genomes segments export from nucleus by NEP protein.
  6. Virus assembly and budding occurs at the plasma membrane.

Host-virus interaction

Innate immune response inhibition

Influenza A virus inhibits the cascade leading to production of interferon-beta by targeting different cellular proteins. NS1 inhibits host RIG-I activation upon recognition of viral RNA, and subsequent induction of IFN-beta expression.

Host protein shutoff

NS1 induces host gene expression shutoff by inducing host mRNA suppression through polyadenlyation inhibition. The viral mRNA are not affected because their polyA tail is generated by polymerase stuttering.

Matching UniProtKB/Swiss-Prot entries

49 entries grouped by strain (browse by keywords)

Only complete proteome entries are shown (view all 174 entries)

13 entries

Influenza A virus (strain A/Goose/Guangdong/1/1996 H5N1 genotype Gs/Gd) reference strain

Select_allDeselect_all
PB2S1_I96A0 PB2-S1
PB2_I96A0 Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
NCAP_I96A0 Nucleoprotein (Nucleocapsid protein) (Protein N)
PAX_I96A0 Protein PA-X
NRAM_I96A0 Neuraminidase (EC 3.2.1.18)
M2_I96A0 Matrix protein 2 (Proton channel protein M2)
PA_I96A0 Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
HEMA_I96A0 Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]
NEP_I96A0 Nuclear export protein (NEP) (Non-structural protein 2) (NS2)
RDRP_I96A0 RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) ...
NS1_I96A0 Non-structural protein 1 (NS1) (NS1A)
M1_I96A0 Matrix protein 1 (M1)
PB1F2_I96A0 Protein PB1-F2

12 entries

Influenza A virus (strain A/Chicken/Scotland/1959 H5N1)

Select_allDeselect_all
HEMA_I59A0 Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]
M2_I59A0 Matrix protein 2 (Proton channel protein M2)
PA_I59A0 Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
PAX_I59A0 Protein PA-X
NCAP_I59A0 Nucleoprotein (Nucleocapsid protein) (Protein N)
M1_I59A0 Matrix protein 1 (M1)
PB2_I59A0 Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
NRAM_I59A0 Neuraminidase (EC 3.2.1.18)
NEP_I59A0 Nuclear export protein (NEP) (Non-structural protein 2) (NS2)
RDRP_I59A0 RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) ...
NS1_I59A0 Non-structural protein 1 (NS1) (NS1A)
PB1F2_I59A0 Protein PB1-F2

12 entries

Influenza A virus (strain A/Duck/Hong Kong/2986.1/2000 H5N1 genotype C)

Select_allDeselect_all
PA_I00A0 Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
NCAP_I00A0 Nucleoprotein (Nucleocapsid protein) (Protein N)
PB2_I00A0 Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
PAX_I00A0 Protein PA-X
M1_I00A0 Matrix protein 1 (M1)
M2_I00A0 Matrix protein 2 (Proton channel protein M2)
HEMA_I00A0 Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]
NRAM_I00A0 Neuraminidase (EC 3.2.1.18)
NS1_I00A0 Non-structural protein 1 (NS1) (NS1A)
PB1F2_I00A0 Protein PB1-F2
NEP_I00A0 Nuclear export protein (NEP) (Non-structural protein 2) (NS2)
RDRP_I00A0 RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) ...

12 entries

Influenza A virus (strain A/Hong Kong/156/1997 H5N1 genotype Gs/Gd)

Select_allDeselect_all
PAX_I97A1 Protein PA-X
RDRP_I97A1 RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) ...
PB2_I97A1 Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
M2_I97A1 Matrix protein 2 (Proton channel protein M2)
HEMA_I97A1 Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]
PA_I97A1 Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
M1_I97A1 Matrix protein 1 (M1)
NCAP_I97A1 Nucleoprotein (Nucleocapsid protein) (Protein N)
NS1_I97A1 Non-structural protein 1 (NS1) (NS1A)
PB1F2_I97A1 Protein PB1-F2
NEP_I97A1 Nuclear export protein (NEP) (Non-structural protein 2) (NS2)
NRAM_I97A1 Neuraminidase (EC 3.2.1.18)