Influenza B virus

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 protein (browse by keywords)

All proteins are shown (view only 21 complete proteome entries)

6 entries

Matrix protein 2 (BM2)

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BM2_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
BM2_INBAC
Influenza B virus (strain B/Ann Arbor/1/1966 [cold-adapted])
BM2_INBAD
Influenza B virus (strain B/Ann Arbor/1/1966 [wild-type])
BM2_INBMP
Influenza B virus (strain B/Memphis/12/1997)
BM2_INBSI
Influenza B virus (strain B/Singapore/222/1979)
BM2_INBYA
Influenza B virus (strain B/Yamagata/1/1973)

6 entries

Hemagglutinin

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HEMA_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
HEMA_INBBE
Influenza B virus (strain B/Beijing/1/1987)
HEMA_INBEN
Influenza B virus (strain B/England/222/1982)
HEMA_INBOR
Influenza B virus (strain B/Oregon/5/1980)
HEMA_INBSI
Influenza B virus (strain B/Singapore/222/1979)
HEMA_INBVK
Influenza B virus (strain B/Victoria/2/1987)

6 entries

Matrix protein 1 (M1)

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M1_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
M1_INBAC
Influenza B virus (strain B/Ann Arbor/1/1966 [cold-adapted])
M1_INBAD
Influenza B virus (strain B/Ann Arbor/1/1966 [wild-type])
M1_INBMP
Influenza B virus (strain B/Memphis/12/1997)
M1_INBSI
Influenza B virus (strain B/Singapore/222/1979)
M1_INBYA
Influenza B virus (strain B/Yamagata/1/1973)

6 entries

Nucleoprotein (Nucleocapsid protein) (Protein N)

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NCAP_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
NCAP_INBAA
Influenza B virus (strain B/Ann Arbor/1/1986)
NCAP_INBAC
Influenza B virus (strain B/Ann Arbor/1/1966 [cold-adapted])
NCAP_INBAD
Influenza B virus (strain B/Ann Arbor/1/1966 [wild-type])
NCAP_INBP9
Influenza B virus (strain B/Panama/45/1990)
NCAP_INBSI
Influenza B virus (strain B/Singapore/222/1979)

2 entries

Nuclear export protein (NEP) (Non-structural protein 2) (NS2)

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NEP_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
NEP_INBYA
Influenza B virus (strain B/Yamagata/1/1973)

12 entries

Neuraminidase (EC 3.2.1.18)

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NRAM_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
NRAM_INBBE
Influenza B virus (strain B/Beijing/1/1987)
NRAM_INBHK
Influenza B virus (strain B/Hong Kong/8/1973)
NRAM_INBLN
Influenza B virus (strain B/Leningrad/179/1986)
NRAM_INBMD
Influenza B virus (strain B/Maryland/1959)
NRAM_INBME
Influenza B virus (strain B/Memphis/6/1986)
NRAM_INBMF
Influenza B virus (strain B/Memphis/3/1989)
NRAM_INBOR
Influenza B virus (strain B/Oregon/5/1980)
NRAM_INBSI
Influenza B virus (strain B/Singapore/222/1979)
NRAM_INBUS
Influenza B virus (strain B/USSR/100/1983)
NRAM_INBVI
Influenza B virus (strain B/Victoria/3/1985)
NRAM_INBYB
Influenza B virus (strain B/Yamagata/16/1988)

16 entries

Non-structural protein 1 (NS1) (NS1A)

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NS1_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
NS1_INBAC
Influenza B virus (strain B/Ann Arbor/1/1966 [cold-adapted])
NS1_INBAD
Influenza B virus (strain B/Ann Arbor/1/1966 [wild-type])
NS1_INBBA
Influenza B virus (strain B/BA/1978)
NS1_INBGA
Influenza B virus (strain B/GA/1986)
NS1_INBGL
Influenza B virus (strain B/GL/1954)
NS1_INBHK
Influenza B virus (strain B/Hong Kong/8/1973)
NS1_INBHT
Influenza B virus (strain B/HT/1984)
NS1_INBID
Influenza B virus (strain B/ID/1986)
NS1_INBMD
Influenza B virus (strain B/Maryland/1959)
NS1_INBPA
Influenza B virus (strain B/PA/1979)
NS1_INBRU
Influenza B virus (strain B/RU/1969)
NS1_INBSI
Influenza B virus (strain B/Singapore/222/1979)
NS1_INBSJ
Influenza B virus (strain B/Singapore/1964)
NS1_INBVJ
Influenza B virus (strain B/Victoria/1987)
NS1_INBYA
Influenza B virus (strain B/Yamagata/1/1973)

5 entries

Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)

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PA_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
PA_INBAC
Influenza B virus (strain B/Ann Arbor/1/1966 [cold-adapted])
PA_INBAD
Influenza B virus (strain B/Ann Arbor/1/1966 [wild-type])
PA_INBP9
Influenza B virus (strain B/Panama/45/1990)
PA_INBSI
Influenza B virus (strain B/Singapore/222/1979)

4 entries

Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)

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PB2_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
PB2_INBAC
Influenza B virus (strain B/Ann Arbor/1/1966 [cold-adapted])
PB2_INBAD
Influenza B virus (strain B/Ann Arbor/1/1966 [wild-type])
PB2_INBP9
Influenza B virus (strain B/Panama/45/1990)

4 entries

RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) (RNA-directed RNA polymerase subunit P1)

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RDRP_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
RDRP_INBAC
Influenza B virus (strain B/Ann Arbor/1/1966 [cold-adapted])
RDRP_INBAD
Influenza B virus (strain B/Ann Arbor/1/1966 [wild-type])
RDRP_INBP9
Influenza B virus (strain B/Panama/45/1990)

11 entries

Glycoprotein NB

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VNB_INBLE
Influenza B virus (strain B/Lee/1940) reference strain
VNB_INBBE
Influenza B virus (strain B/Beijing/1/1987)
VNB_INBHK
Influenza B virus (strain B/Hong Kong/8/1973)
VNB_INBLN
Influenza B virus (strain B/Leningrad/179/1986)
VNB_INBMD
Influenza B virus (strain B/Maryland/1959)
VNB_INBME
Influenza B virus (strain B/Memphis/6/1986)
VNB_INBMF
Influenza B virus (strain B/Memphis/3/1989)
VNB_INBOR
Influenza B virus (strain B/Oregon/5/1980)
VNB_INBSI
Influenza B virus (strain B/Singapore/222/1979)
VNB_INBUS
Influenza B virus (strain B/USSR/100/1983)
VNB_INBVI
Influenza B virus (strain B/Victoria/3/1985)