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)

Genome polyprotein

Select_all Deselect_all  
POLG_DEN1WDengue virus type 1 (strain Nauru/West Pac/1974) (DENV-1) reference strain
POLG_YEFV1Yellow fever virus (strain 17D vaccine) (YFV) reference strain
POLG_ZIKVZika virus (strain Mr 766) (ZIKV) reference strain
POLG_DEN1BDengue virus type 1 (strain Brazil/97-11/1997) (DENV-1)
POLG_DEN1SDengue virus type 1 (strain Singapore/S275/1990) (DENV-1)
POLG_DEN28Dengue virus type 2 (isolate Thailand/0168/1979) (DENV-2)
POLG_DEN27Dengue virus type 2 (strain 16681-PDK53) (DENV-2)
POLG_DEN2JDengue virus type 2 (strain Jamaica/1409/1983) (DENV-2)
POLG_DEN2QDengue virus type 2 (strain Peru/IQT2913/1996) (DENV-2)
POLG_DEN2PDengue virus type 2 (strain Puerto Rico/PR159-S1/1969) (DENV-2)
POLG_DEN26Dengue virus type 2 (strain Thailand/16681/1984) (DENV-2)
POLG_DEN2NDengue virus type 2 (strain Thailand/NGS-C/1944) (DENV-2)
POLG_DEN3CDengue virus type 3 (strain China/80-2/1980) (DENV-3)
POLG_DEN3MDengue virus type 3 (strain Martinique/1243/1999) (DENV-3)
POLG_DEN3PDengue virus type 3 (strain Philippines/H87/1956) (DENV-3)
POLG_DEN3IDengue virus type 3 (strain Singapore/8120/1995) (DENV-3)
POLG_DEN3SDengue virus type 3 (strain Sri Lanka/1266/2000) (DENV-3)
POLG_DEN4DDengue virus type 4 (strain Dominica/814669/1981) (DENV-4)
POLG_DEN4PDengue virus type 4 (strain Philippines/H241/1956) (DENV-4)
POLG_DEN4SDengue virus type 4 (strain Singapore/8976/1995) (DENV-4)
POLG_DEN4TDengue virus type 4 (strain Thailand/0348/1991) (DENV-4)
POLG_DEN4HDengue virus type 4 (strain Thailand/0476/1997) (DENV-4)
POLG_JAEVJJapanese encephalitis virus (strain Jaoars982)
POLG_JAEV5Japanese encephalitis virus (strain SA(v))
POLG_JAEV1Japanese encephalitis virus (strain SA-14)
POLG_KUNJMKunjin virus (strain MRM61C)
POLG_LANVTLangat virus (strain TP21)
POLG_LIVLouping ill virus (Li)
POLG_MCFAMosquito cell fusing agent (CFA flavivirus)
POLG_MVEV5Murray valley encephalitis virus (strain MVE-1-51) (MVEV)
POLG_TBEVHTick-borne encephalitis virus (strain Hypr) (TBEV)
POLG_TBEVWTick-borne encephalitis virus European subtype (strain Neudoerfl) (NEUV) ...
POLG_TBEVSTick-borne encephalitis virus Far Eastern subtype (strain Sofjin) (SOFV) ...
POLG_POWVLTick-borne powassan virus (strain LB) (POWV) (Powassan virus)
POLG_WNVWest Nile virus (WNV)
POLG_YEFVNYellow fever virus (isolate Angola/14FA/1971) (YFV)
POLG_YEFVEYellow fever virus (isolate Ethiopia/Couma/1961) (YFV)
POLG_YEFVCYellow fever virus (isolate Ivory Coast/1999) (YFV)
POLG_YEFVIYellow fever virus (isolate Ivory Coast/85-82H/1982) (YFV)
POLG_YEFVUYellow fever virus (isolate Uganda/A7094A4/1948) (YFV)
POLG_YEFVFYellow fever virus (strain French neurotropic vaccine FNV) (YFV)
POLG_YEFVAYellow fever virus (strain Ghana/Asibi/1927) (YFV)
POLG_YEFVTYellow fever virus (strain Trinidad/TRINID79A/1979) (YFV)