Phlebovirus (taxid:11584)

VIRION

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Enveloped, spherical. Diameter from 80 to 120nm. Glycoproteins at the surface of the envelope are arranged on an icosahedral lattice, with T=12 symmetry.

GENOME

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Segmented Negative-stranded RNA linear genome, L segment is about 6.4kb, M segment about 3.2kb and S segment about 1.7kb.
Encodes for six proteins.

GENE EXPRESSION

Transcription starts by viral RNA dependent RNA polymerase (L) binding to a promoter on each encapsidated segment, and is terminated by a strong hairpin sequence at the end of each gene. These are capped by L protein during synthesis using cap snatching , but are not polyadenylated.
S segment uses ambisense strategy to encode for several proteins: both genomic and antigenomic RNA are transcribed. The hairpin sequence is a stop polymerase signal which prevents ambisense transcription from producing dsRNA. M segment encodes for several polyproteins by leaky scanning, which are cleaved by host protease into Nsm-GN, Nsm, NSm',Gn and Gc proteins.

ENZYMES

REPLICATION

CYTOPLASMIC

  1. Virus attaches to host receptors though Gn-Gc glycoprotein dimer, and is endocytosed into vesicles in the host cell.
  2. Fusion of virus membrane with the vesicle membrane; ribonucleocapsid segments are released in the cytoplasm.
  3. Transcription, viral mRNAs are capped in the cytoplasm.
  4. Replication presumably starts when enough nucleoprotein is present to encapsidate neo-synthetized antigenomes and genomes.
  5. The ribonucleocapsids buds at Golgi apparatus, releasing the virion by exocytosis.

Host-virus interaction

Inhibition of host transcription initiation

The Rift valley fever virus NSs protein instead plays a role in the inhibition of the host transcription initiation by acting on host TFIIH.

Matching UniProtKB/Swiss-Prot entries

(all links/actions below point to uniprot.org website)

19 entries grouped by strain

4 entries

Rift valley fever virus (strain ZH-548 M12) (RVFV) reference strain

Select_allDeselect_all
GP_RVFVZ Envelopment polyprotein (M polyprotein) [Cleaved into: NSm-Gn protein (p78); Glycoprotein N (Gn) ...
NSS_RVFVZ Non-structural protein S (NSs)
L_RVFVZ RNA-directed RNA polymerase L (Protein L) (EC 2.7.7.48) (Large structural protein) (Replicase) ...
NCAP_RVFVZ Nucleoprotein (Nucleocapsid protein) (Protein N)

4 entries

Uukuniemi virus (strain S23) (UUKV) reference strain

Select_allDeselect_all
GP_UUKS Envelopment polyprotein (M polyprotein) (p110) [Cleaved into: Glycoprotein N (Gn) (Glycoprotein G1); ...
L_UUKS RNA-directed RNA polymerase L (Protein L) (EC 2.7.7.48) (Large structural protein) (Replicase) ...
NCAP_UUKS Nucleoprotein (Nucleocapsid protein) (Protein N)
NSS_UUKS Non-structural protein NS-S (NSs)

3 entries

Punta toro phlebovirus

Select_allDeselect_all
GP_PTPV Envelopment polyprotein (M polyprotein) [Cleaved into: NSm-Gn protein; Glycoprotein N (Gn) ...
NCAP_PTPV Nucleoprotein (Nucleocapsid protein) (Protein N)
NSS_PTPV Non-structural protein NS-S

3 entries

Rift valley fever virus (RVFV)

Select_allDeselect_all
L_RVFV RNA-directed RNA polymerase L (Protein L) (EC 2.7.7.48) (Large structural protein) (Replicase) ...
NCAP_RVFV Nucleoprotein (Nucleocapsid protein) (Protein N)
GP_RVFV Envelopment polyprotein (M polyprotein) [Cleaved into: NSm-Gn protein; Glycoprotein N (Gn) ...

3 entries

Toscana virus (Tos)

Select_allDeselect_all
L_TOSV RNA-directed RNA polymerase L (Protein L) (EC 2.7.7.48) (Large structural protein) (Replicase) ...
NCAP_TOSV Nucleoprotein (Nucleocapsid protein) (Protein N)
NSS_TOSV Non-structural protein NS-S (NSs)

2 entries

Sandfly fever sicilian virus (SFS)

Select_allDeselect_all
NCAP_SFSV Nucleoprotein (Nucleocapsid protein) (Protein N)
NSS_SFSV Non-structural protein NS-S