Influenza B virus

Molecular biology

VIRION

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 11 proteins. 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 snatching. mRNA are polyadenylated by the viral polymerase stuttering on a poly U track. M and NS mRNA can be alternatively spliced, giving rise to mRNA coding for BM” and NEP proteins. NB is translated by leaky scanning from the NA mRNA.

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 B virus inhibits the cascade leading to production of interferon-beta by targeting different cellular proteins. NS1 inhibits host ISG15 activation as well as PKR.

Matching UniProtKB/Swiss-Prot entries

78 entries grouped by strain (browse by keywords)

All proteins are shown (view only 11 complete proteome entries)

11 entries

Influenza B virus (strain B/Lee/1940) reference strain

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BM2_INBLEMatrix protein 2 (BM2)
HEMA_INBLEHemagglutinin
M1_INBLEMatrix protein 1 (M1)
NCAP_INBLENucleoprotein (Nucleocapsid protein) (Protein N)
NEP_INBLENuclear export protein (NEP) (Non-structural protein 2) (NS2)
NRAM_INBLENeuraminidase (EC 3.2.1.18)
NS1_INBLENon-structural protein 1 (NS1) (NS1B)
PA_INBLEPolymerase acidic protein (RNA-directed RNA polymerase subunit P2)
PB2_INBLEPolymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
RDRP_INBLERNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic ...
VNB_INBLEGlycoprotein NB

8 entries

Influenza B virus (strain B/Singapore/222/1979)

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BM2_INBSIMatrix protein 2 (BM2)
HEMA_INBSIHemagglutinin
M1_INBSIMatrix protein 1 (M1)
NCAP_INBSINucleoprotein (Nucleocapsid protein) (Protein N)
NRAM_INBSINeuraminidase (EC 3.2.1.18)
NS1_INBSINon-structural protein 1 (NS1) (NS1B)
PA_INBSIPolymerase acidic protein (RNA-directed RNA polymerase subunit P2)
VNB_INBSIGlycoprotein NB

7 entries

Influenza B virus (strain B/Ann Arbor/1/1966 [cold-adapted])

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BM2_INBACMatrix protein 2 (BM2)
M1_INBACMatrix protein 1 (M1)
NCAP_INBACNucleoprotein (Nucleocapsid protein) (Protein N)
NS1_INBACNon-structural protein 1 (NS1) (NS1B)
PA_INBACPolymerase acidic protein (RNA-directed RNA polymerase subunit P2)
PB2_INBACPolymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
RDRP_INBACRNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic ...

7 entries

Influenza B virus (strain B/Ann Arbor/1/1966 [wild-type])

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BM2_INBADMatrix protein 2 (BM2)
M1_INBADMatrix protein 1 (M1)
NCAP_INBADNucleoprotein (Nucleocapsid protein) (Protein N)
NS1_INBADNon-structural protein 1 (NS1) (NS1B)
PA_INBADPolymerase acidic protein (RNA-directed RNA polymerase subunit P2)
PB2_INBADPolymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
RDRP_INBADRNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic ...

4 entries

Influenza B virus (strain B/Panama/45/1990)

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NCAP_INBP9Nucleoprotein (Nucleocapsid protein) (Protein N)
PA_INBP9Polymerase acidic protein (RNA-directed RNA polymerase subunit P2)
PB2_INBP9Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
RDRP_INBP9RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic ...

4 entries

Influenza B virus (strain B/Yamagata/1/1973)

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BM2_INBYAMatrix protein 2 (BM2)
M1_INBYAMatrix protein 1 (M1)
NEP_INBYANuclear export protein (NEP) (Non-structural protein 2) (NS2)
NS1_INBYANon-structural protein 1 (NS1) (NS1B)

3 entries

Influenza B virus (strain B/Beijing/1/1987)

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HEMA_INBBEHemagglutinin
NRAM_INBBENeuraminidase (EC 3.2.1.18)
VNB_INBBEGlycoprotein NB

3 entries

Influenza B virus (strain B/Hong Kong/8/1973)

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NRAM_INBHKNeuraminidase (EC 3.2.1.18)
NS1_INBHKNon-structural protein 1 (NS1) (NS1B)
VNB_INBHKGlycoprotein NB

3 entries

Influenza B virus (strain B/Maryland/1959)

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NRAM_INBMDNeuraminidase (EC 3.2.1.18)
NS1_INBMDNon-structural protein 1 (NS1) (NS1B)
VNB_INBMDGlycoprotein NB

3 entries

Influenza B virus (strain B/Oregon/5/1980)

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HEMA_INBORHemagglutinin
NRAM_INBORNeuraminidase (EC 3.2.1.18)
VNB_INBORGlycoprotein NB

2 entries

Influenza B virus (strain B/Leningrad/179/1986)

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NRAM_INBLNNeuraminidase (EC 3.2.1.18)
VNB_INBLNGlycoprotein NB

2 entries

Influenza B virus (strain B/Memphis/12/1997)

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BM2_INBMPMatrix protein 2 (BM2)
M1_INBMPMatrix protein 1 (M1)

2 entries

Influenza B virus (strain B/Memphis/3/1989)

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NRAM_INBMFNeuraminidase (EC 3.2.1.18)
VNB_INBMFGlycoprotein NB

2 entries

Influenza B virus (strain B/Memphis/6/1986)

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NRAM_INBMENeuraminidase (EC 3.2.1.18)
VNB_INBMEGlycoprotein NB

2 entries

Influenza B virus (strain B/USSR/100/1983)

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NRAM_INBUSNeuraminidase (EC 3.2.1.18)
VNB_INBUSGlycoprotein NB

2 entries

Influenza B virus (strain B/Victoria/3/1985)

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NRAM_INBVINeuraminidase (EC 3.2.1.18)
VNB_INBVIGlycoprotein NB

1 entry

Influenza B virus (strain B/Ann Arbor/1/1986)


NCAP_INBAANucleoprotein (Nucleocapsid protein) (Protein N)

1 entry

Influenza B virus (strain B/BA/1978)


NS1_INBBANon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/England/222/1982)


HEMA_INBENHemagglutinin

1 entry

Influenza B virus (strain B/GA/1986)


NS1_INBGANon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/GL/1954)


NS1_INBGLNon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/HT/1984)


NS1_INBHTNon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/ID/1986)


NS1_INBIDNon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/PA/1979)


NS1_INBPANon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/RU/1969)


NS1_INBRUNon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/Singapore/1964)


NS1_INBSJNon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/Victoria/1987)


NS1_INBVJNon-structural protein 1 (NS1) (NS1B)

1 entry

Influenza B virus (strain B/Victoria/2/1987)


HEMA_INBVKHemagglutinin

1 entry

Influenza B virus (strain B/Yamagata/16/1988)


NRAM_INBYBNeuraminidase (EC 3.2.1.18)