Flavivirus

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VIRION

Enveloped, spherical, about 50 nm in diameter. The surface proteins are arranged in an icosahedral-like symmetry. Mature virions contain two virus-encoded membrane proteins (M and E), while immature virions contain a membrane protein precursor.
Source: Zhang et al(Pubmed )

GENOME

Monopartite, linear, ssRNA(+) genome of of 10-11 kb. The genome 5' end has a methylated nucleotide cap for canonical cellular translation. The 3' terminus is not polyadenylated but forms a loop structure. This secondary structure leads to the formation of a subgenomic flavivirus RNA (sfRNA) through genomic RNA degradation by host XRN1. sfRNA is essential for pathogenicity , and may play a role in inhibiting host RIG-I antiviral activity as shown for Dengue virus

GENE EXPRESSION

The virion RNA is infectious and serves as both the genome and the viral messenger RNA. The whole genome is translated in a polyprotein, which is processed co- and post-translationally by host and viral proteases.

REPLICATION

  1. Attachement of the viral envelope protein E to host receptors mediates internalization into the host cell by clathrin-mediated endocytosis, or by apoptotic mimicry
  2. Fusion of virus membrane with host endosomal membrane. RNA genome is released into the cytoplasm.
  3. The positive-sense genomic ssRNA is translated into a polyprotein, which is cleaved into all structural and non structural proteins (to yield the replication proteins).
  4. Replication takes place at the surface of endoplasmic reticulum in cytoplasmic viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
  5. The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
  6. Virus assembly occurs at the endoplasmic reticulum. The virion buds at the endoplasmic reticulum and is transported to the Golgi apparatus.
  7. The prM protein is cleaved in the Golgi, thereby maturing the virion which is fusion competent.
  8. Release of new virions by exocytosis.

Host-virus interaction

Adaptive immune response inhibition

Dengue NS1 protein inhibits host complement by binding C4 and reducing C4b deposition and C3 convertase activity. Through this mechanism, NS1 protects DENV from complement-dependent neutralization in solution .

Apoptosis modulation

Flaviviruses NS3 induces apoptosis through host caspases activation .

Autophagy modulation

Flaviviruses NS4A and NS4B induces autophagy signaling .

Innate immune response inhibition

Dengue virus blocks STAT2 .

Matching UniProtKB/Swiss-Prot entries

43 entries grouped by protein (browse by keywords)

43 entries

Genome polyprotein

Select_allDeselect_all
POLG_DEN1W
Dengue virus type 1 (strain Nauru/West Pac/1974) (DENV-1) reference strain
POLG_YEFV1
Yellow fever virus (strain 17D vaccine) (YFV) reference strain
POLG_ZIKV
Zika virus (strain Mr 766) (ZIKV) reference strain
POLG_DEN1B
Dengue virus type 1 (strain Brazil/97-11/1997) (DENV-1)
POLG_DEN1S
Dengue virus type 1 (strain Singapore/S275/1990) (DENV-1)
POLG_DEN26
Dengue virus type 2 (strain Thailand/16681/1984) (DENV-2)
POLG_DEN27
Dengue virus type 2 (strain 16681-PDK53) (DENV-2)
POLG_DEN28
Dengue virus type 2 (isolate Thailand/0168/1979) (DENV-2)
POLG_DEN2J
Dengue virus type 2 (strain Jamaica/1409/1983) (DENV-2)
POLG_DEN2N
Dengue virus type 2 (strain Thailand/NGS-C/1944) (DENV-2)
POLG_DEN2P
Dengue virus type 2 (strain Puerto Rico/PR159-S1/1969) (DENV-2)
POLG_DEN2Q
Dengue virus type 2 (strain Peru/IQT2913/1996) (DENV-2)
POLG_DEN3C
Dengue virus type 3 (strain China/80-2/1980) (DENV-3)
POLG_DEN3I
Dengue virus type 3 (strain Singapore/8120/1995) (DENV-3)
POLG_DEN3M
Dengue virus type 3 (strain Martinique/1243/1999) (DENV-3)
POLG_DEN3P
Dengue virus type 3 (strain Philippines/H87/1956) (DENV-3)
POLG_DEN3S
Dengue virus type 3 (strain Sri Lanka/1266/2000) (DENV-3)
POLG_DEN4D
Dengue virus type 4 (strain Dominica/814669/1981) (DENV-4)
POLG_DEN4H
Dengue virus type 4 (strain Thailand/0476/1997) (DENV-4)
POLG_DEN4P
Dengue virus type 4 (strain Philippines/H241/1956) (DENV-4)
POLG_DEN4S
Dengue virus type 4 (strain Singapore/8976/1995) (DENV-4)
POLG_DEN4T
Dengue virus type 4 (strain Thailand/0348/1991) (DENV-4)
POLG_JAEV1
Japanese encephalitis virus (strain SA-14)
POLG_JAEV5
Japanese encephalitis virus (strain SA(v))
POLG_JAEVJ
Japanese encephalitis virus (strain Jaoars982)
POLG_KUNJM
Kunjin virus (strain MRM61C)
POLG_LANVT
Langat virus (strain TP21)
POLG_LIV
Louping ill virus (Li)
POLG_MCFA
Mosquito cell fusing agent (CFA flavivirus)
POLG_MVEV5
Murray valley encephalitis virus (strain MVE-1-51) (MVEV)
POLG_POWVL
Tick-borne powassan virus (strain LB) (POWV) (Powassan virus)
POLG_TBEVH
Tick-borne encephalitis virus (strain Hypr) (TBEV)
POLG_TBEVS
Tick-borne encephalitis virus Far Eastern subtype (strain Sofjin) (SOFV) (Sofjin virus)
POLG_TBEVW
Tick-borne encephalitis virus European subtype (strain Neudoerfl) (NEUV) (Neudoerfl virus)
POLG_WNV
West Nile virus (WNV)
POLG_YEFVA
Yellow fever virus (strain Ghana/Asibi/1927) (YFV)
POLG_YEFVC
Yellow fever virus (isolate Ivory Coast/1999) (YFV)
POLG_YEFVE
Yellow fever virus (isolate Ethiopia/Couma/1961) (YFV)
POLG_YEFVF
Yellow fever virus (strain French neurotropic vaccine FNV) (YFV)
POLG_YEFVI
Yellow fever virus (isolate Ivory Coast/85-82H/1982) (YFV)
POLG_YEFVN
Yellow fever virus (isolate Angola/14FA/1971) (YFV)
POLG_YEFVT
Yellow fever virus (strain Trinidad/TRINID79A/1979) (YFV)
POLG_YEFVU
Yellow fever virus (isolate Uganda/A7094A4/1948) (YFV)