Editing Rotavirus (section)

==== Nonstructural viral proteins ====
NSP1, the product of gene 5, is a [[nonstructural protein|nonstructural]] RNA-binding protein.<ref>{{cite journal |vauthors=Hua J, Mansell EA, Patton JT |title=Comparative analysis of the rotavirus NS53 gene: conservation of basic and cysteine-rich regions in the protein and possible stem-loop structures in the RNA |journal=Virology |volume=196 |issue=1 |pages=372–378 |year=1993 |pmid=8395125 |doi=10.1006/viro.1993.1492|doi-access=free }}</ref> NSP1 also blocks the [[interferon]] response, the part of the [[innate immune system]] that protects cells from viral infection. NSP1 causes the [[proteosome]] to degrade key signaling components required to stimulate production of interferon in an infected cell and to respond to interferon secreted by adjacent cells.

Targets for degradation include several [[interferon regulatory factors|IRF]] transcription factors required for interferon gene transcription.<ref name=Arnold2016>{{cite journal |vauthors=Arnold MM |title=The Rotavirus Interferon Antagonist NSP1: Many Targets, Many Questions |journal=Journal of Virology |volume=90 |issue=11 |pages=5212–5215 |year=2016 |pmid=27009959 |doi=10.1128/JVI.03068-15 |pmc=4934742 }}</ref>

NSP2 is an [[RNA-binding protein]] that accumulates in cytoplasmic inclusions ([[viroplasm]]s) and is required for genome replication.<ref>{{cite journal |vauthors=Kattoura MD, Chen X, Patton JT |title=The rotavirus RNA-binding protein NS35 (NSP2) forms 10S multimers and interacts with the viral RNA polymerase |journal=Virology |volume=202 |issue=2 |pages=803–13 |year=1994 |pmid=8030243 |doi=10.1006/viro.1994.1402|doi-access=free }}</ref><ref name="pmid15010217" />

NSP3 is bound to viral mRNAs in infected cells and it is responsible for the shutdown of cellular protein synthesis.<ref>{{cite journal |title=Rotavirus protein NSP3 (NS34) is bound to the 3' end consensus sequence of viral mRNAs in infected cells
|journal=Journal of Virology |volume=67 |issue=6 |pages=3159–3165 |year=1993|pmid=8388495 |url=http://jvi.asm.org/cgi/reprint/67/6/3159 |format=PDF |pmc=237654 |vauthors=Poncet D, Aponte C, [[Jean Cohen|Cohen J]]|doi=10.1128/JVI.67.6.3159-3165.1993 }}</ref> NSP3 inactivates two translation initiation factors essential for synthesis of proteins from host mRNA.

First, NSP3 ejects [[poly(A)-binding protein]] (PABP) from the translation initiation factor [[eIF4F]].  PABP is required for efficient translation of transcripts with a 3' [[poly(A) tail]], which is found on most host cell transcripts. Second, NSP3 inactivates [[eIF2]] by stimulating its phosphorylation.<ref name="pmid26727111">{{cite journal |vauthors=Gratia M, Vende P, Charpilienne A, Baron HC, Laroche C, Sarot E, Pyronnet S, Duarte M, Poncet D |title=Challenging the Roles of NSP3 and Untranslated Regions in Rotavirus mRNA Translation |journal=PLOS ONE |volume=11 |issue=1 |pages=e0145998 |year=2016 |pmid=26727111 |pmc=4699793 |doi=10.1371/journal.pone.0145998 |bibcode=2016PLoSO..1145998G |doi-access=free }}</ref> Efficient translation of rotavirus mRNA, which lacks the 3' poly(A) tail, does not require either of these factors.<ref name="Lopez2012">{{cite journal|vauthors=López S, Arias CF|title=Rotavirus-host cell interactions: an arms race|journal=Current Opinion in Virology|year=2012|volume=2|issue=4|pages=389–398|doi=10.1016/j.coviro.2012.05.001|pmid=22658208}}</ref>

NSP4 is a viral [[enterotoxin]] that induces diarrhoea and was the first viral enterotoxin discovered.<ref name="pmid19114772">{{cite journal |vauthors=Hyser JM, Estes MK |title=Rotavirus vaccines and pathogenesis: 2008 |journal=Current Opinion in Gastroenterology |volume=25 |issue=1 |pages=36–43 |year=2009 |pmid=19114772 |pmc=2673536 |doi=10.1097/MOG.0b013e328317c897 }}</ref> It is a [[viroporin]] that elevates cytosolic Ca<sup>2+</sup> in mammalian cells.<ref name="pmid28256607">{{cite journal |vauthors=Pham T, Perry JL, Dosey TL, Delcour AH, Hyser JM |title=The Rotavirus NSP4 Viroporin Domain is a Calcium-conducting Ion Channel |journal=Scientific Reports |volume=7 |issue= |pages=43487 |date=March 2017 |pmid=28256607 |pmc=5335360 |doi=10.1038/srep43487 |bibcode=2017NatSR...743487P |url=}}</ref>

NSP5 is encoded by genome segment 11 of rotavirus A. In virus-infected cells NSP5 accumulates in the viroplasm.<ref>{{cite journal |vauthors=Afrikanova I, Miozzo MC, Giambiagi S, Burrone O |title=Phosphorylation generates different forms of rotavirus NSP5 |journal=Journal of General Virology |volume=77 |pages=2059–2065 |year=1996 |pmid=8811003 |doi=10.1099/0022-1317-77-9-2059 |issue=9 |doi-access=free }}</ref>

NSP6 is a nucleic acid binding protein<ref>{{cite journal |vauthors=Rainsford EW, McCrae MA |title=Characterization of the NSP6 protein product of rotavirus gene 11 |journal=Virus Research |volume=130 |issue=1–2 |pages=193–201 |year=2007 |pmid=17658646 |doi=10.1016/j.virusres.2007.06.011}}</ref> and is encoded by gene 11 from an out-of-phase [[open reading frame]].<ref>{{cite journal |vauthors=Mohan KV, Atreya CD |s2cid=21538632 |title=Nucleotide sequence analysis of rotavirus gene 11 from two tissue culture-adapted ATCC strains, RRV and Wa |journal=Virus Genes |volume=23 |issue=3 |pages=321–329 |year=2001 |pmid=11778700 |doi=10.1023/A:1012577407824}}</ref>

{| class="wikitable" style="text-align:center"
|+ Rotavirus genes and proteins
! RNA Segment (Gene) !! Size ([[base pair]]s) !! Protein !! [[UniProt]] !! Molecular weight [[Atomic mass unit|kDa]] !! Location !! Copies per particle !! Function
|-
! 1
| 3302 || VP1 || {{UniProt|P22678}} || 125 || At the vertices of the core || 12 || RNA-dependent RNA polymerase
|-
! 2
| 2690 || VP2 || {{UniProt|A2T3R5}} || 102 || Forms inner shell of the core || 120 || RNA binding
|-
! 3
| 2591 || VP3 || {{UniProt|A2T3S5}} || 88 || At the vertices of the  core || 12 || methyltransferase mRNA capping enzyme
|-
! 4
| 2362 || VP4 || {{UniProt|A2T3T2}} || 87 || Surface spike || 180 (60 [[trimers]])<ref name="pmid36996819">{{cite journal |vauthors=Shah PN, Gilchrist JB, Forsberg BO, Burt A, Howe A, Mosalaganti S, Wan W, Radecke J, Chaban Y, Sutton G, Stuart DI, Boyce M |title=Characterization of the rotavirus assembly pathway in situ using cryoelectron tomography |journal=Cell Host & Microbe |volume=31 |issue=4 |pages=604–615.e4 |date=April 2023 |pmid=36996819 |pmc=7615348 |doi=10.1016/j.chom.2023.03.004 |url=}}</ref>  || Cell attachment, virulence
|-
!5
| 1611 || [[NSP1 (rotavirus)|NSP1]] || {{UniProt|Q99FX5}} || 59 || Nonstructural || 0 || 5'RNA binding, interferon antagonist
|-
!6
| 1356 || VP6 || {{UniProt|Q6LE89}} || 45 || Inner Capsid || 780 (260 trimers)<ref name="pmid36996819"/>|| Structural and species-specific antigen
|-
!7
| 1104 || [[NSP3 (rotavirus)|NSP3]] || {{UniProt|P03536}} || 37 || Nonstructural || 0 || Enhances viral mRNA activity and shut-offs  cellular protein synthesis
|-
!8
| 1059 || [[NSP2 (rotavirus)|NSP2]] || {{UniProt|A2T3P0}} || 35 || Nonstructural || 0 || NTPase involved in RNA packaging
|-
!9
| 1062 || VP7{{sup|1}} VP7{{sup|2}} || {{UniProt|P03533}} || 38 and 34 || Surface || 780 (260 trimers)<ref name="pmid36996819"/>  || Structural and neutralisation  antigen
|-
!10
| 751 || [[NSP4 (rotavirus)|NSP4]] || {{UniProt|P04512}} || 20 || Nonstructural || 0 || Viroporin ([[enterotoxin]])
|-
!11
| 667 || [[NSP5 (rotavirus)|NSP5]] [[NSP6 (rotavirus)|NSP6]] || {{UniProt|A2T3Q9}} {{UniProt|P11203}} || 22 || Nonstructural || 0 || ssRNA and dsRNA binding modulator of [[NSP2 (rotavirus)|NSP2]], phosphoprotein
|}
This table is based on the [[simian]] rotavirus strain SA11. RNA-protein coding assignments differ in some strains.