Editing Rift Valley fever (section)

== Pathogenesis ==
Although many components of the RVFV's RNA play an important role in the virus' pathology, the nonstructural protein encoded on the S segment (NSs) is the only component that has been found to directly affect the host. NSs is hostile and combative against the host interferon (IFNs) antiviral response.<ref name=":0">{{cite journal | vauthors = Boshra H, Lorenzo G, Busquets N, Brun A | title = Rift valley fever: recent insights into pathogenesis and prevention | journal = Journal of Virology | volume = 85 | issue = 13 | pages = 6098–105 | date = July 2011 | pmid = 21450816 | pmc = 3126526 | doi = 10.1128/JVI.02641-10 }}</ref> IFNs are essential for the immune system to fight off viral infections in a host.<ref>{{cite journal | vauthors = Fensterl V, Sen GC | title = Interferons and viral infections | journal = BioFactors | volume = 35 | issue = 1 | pages = 14–20 | date = 2009-01-01 | pmid = 19319841 | doi = 10.1002/biof.6 | s2cid = 27209861 }}</ref> This inhibitory mechanism is believed to be due to several reasons, the first being, competitive inhibition of the formation of the transcription factor.<ref name=":0" /> On this transcription factor, NSs interacts with and binds to a subunit that is needed for RNA polymerase I and II.<ref name=":0" /><ref name=":1">{{cite journal | vauthors = Ikegami T, Makino S | title = The pathogenesis of Rift Valley fever | journal = Viruses | volume = 3 | issue = 5 | pages = 493–519 | date = May 2011 | pmid = 21666766 | pmc = 3111045 | doi = 10.3390/v3050493 | doi-access = free }}</ref> This interaction cause competitive inhibition with another transcription factor component and prevents the assembly process of the transcription factor complex, which results in the suppression of the host antiviral response.<ref name=":0" /><ref name=":1" /> Transcription suppression is believed to be another mechanism of this inhibitory process.<ref name=":0" /> This occurs when an area of NSs interacts with and binds to the host's protein, SAP30 and forms a complex.<ref name=":0" /><ref name=":1" /> This complex causes histone acetylation to regress, which is needed for transcriptional activation of the IFN promoter.<ref name=":1" /> This causes IFN expression to be obstructed. Lastly, NSs has also been known to affect regular activity of double-stranded RNA-dependent protein kinase R. This protein is involved in cellular antiviral responses in the host. When RVFV can enter the host's DNA, NSs forms a filamentous structure in the nucleus. This allows the virus to interact with specific areas of the host's DNA that relates to segregation defects and induction of chromosome continuity. This increases host infectivity and decreases the host's antiviral response.<ref name=":0" />