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 strain (browse by keywords)

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

11 entries

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

Select_allDeselect_all
BM2_INBLE Matrix protein 2 (BM2)
NCAP_INBLE Nucleoprotein (Nucleocapsid protein) (Protein N)
NEP_INBLE Nuclear export protein (NEP) (Non-structural protein 2) (NS2)
NRAM_INBLE Neuraminidase (EC 3.2.1.18)
NS1_INBLE Non-structural protein 1 (NS1) (NS1A)
HEMA_INBLE Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]
M1_INBLE Matrix protein 1 (M1)
PB2_INBLE Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
PA_INBLE Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
RDRP_INBLE RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) ...
VNB_INBLE Glycoprotein NB

8 entries

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

Select_allDeselect_all
BM2_INBSI Matrix protein 2 (BM2)
HEMA_INBSI Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]
NRAM_INBSI Neuraminidase (EC 3.2.1.18)
NS1_INBSI Non-structural protein 1 (NS1) (NS1A)
M1_INBSI Matrix protein 1 (M1)
NCAP_INBSI Nucleoprotein (Nucleocapsid protein) (Protein N)
PA_INBSI Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
VNB_INBSI Glycoprotein NB

7 entries

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

Select_allDeselect_all
BM2_INBAC Matrix protein 2 (BM2)
NS1_INBAC Non-structural protein 1 (NS1) (NS1A)
M1_INBAC Matrix protein 1 (M1)
NCAP_INBAC Nucleoprotein (Nucleocapsid protein) (Protein N)
PB2_INBAC Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
PA_INBAC Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
RDRP_INBAC RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) ...

7 entries

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

Select_allDeselect_all
BM2_INBAD Matrix protein 2 (BM2)
NS1_INBAD Non-structural protein 1 (NS1) (NS1A)
M1_INBAD Matrix protein 1 (M1)
NCAP_INBAD Nucleoprotein (Nucleocapsid protein) (Protein N)
PB2_INBAD Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
PA_INBAD Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
RDRP_INBAD RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) ...

4 entries

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

Select_allDeselect_all
NCAP_INBP9 Nucleoprotein (Nucleocapsid protein) (Protein N)
PB2_INBP9 Polymerase basic protein 2 (RNA-directed RNA polymerase subunit P3)
PA_INBP9 Polymerase acidic protein (EC 3.1.-.-) (RNA-directed RNA polymerase subunit P2)
RDRP_INBP9 RNA-directed RNA polymerase catalytic subunit (EC 2.7.7.48) (Polymerase basic protein 1) (PB1) ...

4 entries

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

Select_allDeselect_all
BM2_INBYA Matrix protein 2 (BM2)
NS1_INBYA Non-structural protein 1 (NS1) (NS1A)
M1_INBYA Matrix protein 1 (M1)
NEP_INBYA Nuclear export protein (NEP) (Non-structural protein 2) (NS2)

3 entries

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

Select_allDeselect_all
NRAM_INBBE Neuraminidase (EC 3.2.1.18)
HEMA_INBBE Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]
VNB_INBBE Glycoprotein NB

3 entries

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

Select_allDeselect_all
NRAM_INBHK Neuraminidase (EC 3.2.1.18)
NS1_INBHK Non-structural protein 1 (NS1) (NS1A)
VNB_INBHK Glycoprotein NB

3 entries

Influenza B virus (strain B/Maryland/1959)

Select_allDeselect_all
NRAM_INBMD Neuraminidase (EC 3.2.1.18)
NS1_INBMD Non-structural protein 1 (NS1) (NS1A)
VNB_INBMD Glycoprotein NB

3 entries

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

Select_allDeselect_all
NRAM_INBOR Neuraminidase (EC 3.2.1.18)
HEMA_INBOR Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]
VNB_INBOR Glycoprotein NB

2 entries

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

Select_allDeselect_all
NRAM_INBLN Neuraminidase (EC 3.2.1.18)
VNB_INBLN Glycoprotein NB

2 entries

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

Select_allDeselect_all
BM2_INBMP Matrix protein 2 (BM2)
M1_INBMP Matrix protein 1 (M1)

2 entries

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

Select_allDeselect_all
NRAM_INBMF Neuraminidase (EC 3.2.1.18)
VNB_INBMF Glycoprotein NB

2 entries

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

Select_allDeselect_all
NRAM_INBME Neuraminidase (EC 3.2.1.18)
VNB_INBME Glycoprotein NB

2 entries

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

Select_allDeselect_all
NRAM_INBUS Neuraminidase (EC 3.2.1.18)
VNB_INBUS Glycoprotein NB

2 entries

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

Select_allDeselect_all
NRAM_INBVI Neuraminidase (EC 3.2.1.18)
VNB_INBVI Glycoprotein NB

1 entry

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

NCAP_INBAA Nucleoprotein (Nucleocapsid protein) (Protein N)

1 entry

Influenza B virus (strain B/BA/1978)

NS1_INBBA Non-structural protein 1 (NS1) (NS1A)

1 entry

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

HEMA_INBEN Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]

1 entry

Influenza B virus (strain B/GA/1986)

NS1_INBGA Non-structural protein 1 (NS1) (NS1A)

1 entry

Influenza B virus (strain B/GL/1954)

NS1_INBGL Non-structural protein 1 (NS1) (NS1A)

1 entry

Influenza B virus (strain B/HT/1984)

NS1_INBHT Non-structural protein 1 (NS1) (NS1A)

1 entry

Influenza B virus (strain B/ID/1986)

NS1_INBID Non-structural protein 1 (NS1) (NS1A)

1 entry

Influenza B virus (strain B/PA/1979)

NS1_INBPA Non-structural protein 1 (NS1) (NS1A)

1 entry

Influenza B virus (strain B/RU/1969)

NS1_INBRU Non-structural protein 1 (NS1) (NS1A)

1 entry

Influenza B virus (strain B/Singapore/1964)

NS1_INBSJ Non-structural protein 1 (NS1) (NS1A)

1 entry

Influenza B virus (strain B/Victoria/1987)

NS1_INBVJ Non-structural protein 1 (NS1) (NS1A)

1 entry

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

HEMA_INBVK Hemagglutinin [Cleaved into: Hemagglutinin HA1 chain; Hemagglutinin HA2 chain]

1 entry

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

NRAM_INBYB Neuraminidase (EC 3.2.1.18)