BioPAX pathway converted from "ISGylation of viral protein NS1" in the Reactome database.6.3.2.19ISGylation of viral protein NS1ISGylation of viral protein NS1Some viral proteins are also targeted for ISGylation. The well studied viral protein ISGylation is the modification of the influenza A viral protein NS1, which functions as an IFN antagonist during viral infection. Studies identified seven lysine residues in NS1 as potential ISGylation sites among which K41 (Zhao et al. 2010), K126 and K217 (Tang et al. 2010) were found to be critical. ISGylation at these sites disrupts NS1 association with importin-alpha, a protein required for the nuclear import of NS1.Authored: Garapati, P V, 2011-01-18Reviewed: Zhang, DE, 2011-02-10Edited: Garapati, P V, 2011-01-18Reactome DB_ID: 11693831cytosolGO0005829ISG15:UBCH8:ISG15 E3 ligase [cytosol]ISG15:UBCH8:ISG15 E3 ligaseReactome DB_ID: 11693851ISG15:UBCH8 [cytosol]ISG15:UBCH8Reactome DB_ID: 9365521UniProt:P05161 ISG15ISG15ISG15UCRPG1P2FUNCTION Ubiquitin-like protein which plays a key role in the innate immune response to viral infection either via its conjugation to a target protein (ISGylation) or via its action as a free or unconjugated protein. ISGylation involves a cascade of enzymatic reactions involving E1, E2, and E3 enzymes which catalyze the conjugation of ISG15 to a lysine residue in the target protein. Its target proteins include IFIT1, MX1/MxA, PPM1B, UBE2L6, UBA7, CHMP5, CHMP2A, CHMP4B and CHMP6. Can also isgylate: EIF2AK2/PKR which results in its activation, DDX58/RIG-I which inhibits its function in antiviral signaling response, EIF4E2 which enhances its cap structure-binding activity and translation-inhibition activity, UBE2N and UBE2E1 which negatively regulates their activity, IRF3 which inhibits its ubiquitination and degradation and FLNB which prevents its ability to interact with the upstream activators of the JNK cascade thereby inhibiting IFNA-induced JNK signaling. Exhibits antiviral activity towards both DNA and RNA viruses, including influenza A, HIV-1 and Ebola virus. Restricts HIV-1 and ebola virus via disruption of viral budding. Inhibits the ubiquitination of HIV-1 Gag and host TSG101 and disrupts their interaction, thereby preventing assembly and release of virions from infected cells. Inhibits Ebola virus budding mediated by the VP40 protein by disrupting ubiquitin ligase activity of NEDD4 and its ability to ubiquitinate VP40. ISGylates influenza A virus NS1 protein which causes a loss of function of the protein and the inhibition of virus replication. The secreted form of ISG15 can: induce natural killer cell proliferation, act as a chemotactic factor for neutrophils and act as a IFN-gamma-inducing cytokine playing an essential role in antimycobacterial immunity. The secreted form acts through the integrin ITGAL/ITGB2 receptor to initiate activation of SRC family tyrosine kinases including LYN, HCK and FGR which leads to secretion of IFNG and IL10; the interaction is mediated by ITGAL (PubMed:29100055).SUBUNIT Homodimer; disulfide-linked (PubMed:2440890). Interacts with, and is conjugated to its targets by UBE1L (E1 enzyme) and UBE2E2 (E2 enzyme) (PubMed:11157743, PubMed:15131269). Interacts with NEDD4 (PubMed:18305167).SUBUNIT (Microbial infection) Interacts with vaccinia virus protein E3.SUBUNIT (Microbial infection) Interaction with influenza B NS1 protein inhibits its conjugation.TISSUE SPECIFICITY Detected in lymphoid cells, striated and smooth muscle, several epithelia and neurons. Expressed in neutrophils, monocytes and lymphocytes. Enhanced expression seen in pancreatic adenocarcinoma, endometrial cancer, and bladder cancer, as compared to non-cancerous tissue. In bladder cancer, the increase in expression exhibits a striking positive correlation with more advanced stages of the disease.INDUCTION Strongly induced upon exposure to type I interferons, viruses, LPS, and other stresses, including certain genotoxic stresses.DOMAIN Both the Ubiquitin-like 1 and Ubiquitin-like 2 domains are required for its efficient conjugation to cellular proteins. The two domains play different roles in the ISGylation pathway: Ubiquitin-like 2 domain is necessary for the first two steps allowing the linking of ISG15 to the E1 and E2 enzymes while Ubiquitin-like 1 domain is essential for the final, E3-mediated transfer of ISG15, from the E2 to the Lys of the target protein (PubMed:18356159).PTM S-nitrosylation decreases its dimerization, thereby increasing the availability as well as the solubility of monomeric ISG15 for its conjugation to cellular proteins.PTM Induced as an inactive, precursor protein that is cleaved by specific proteases to expose the C-terminal diglycine (LRLRGG) motif. This motif is essential not only for its conjugation to substrates but also for its recognition by the relevant processing proteases.Reactomehttp://www.reactome.orgHomo sapiensNCBI Taxonomy9606UniProtP05161Chain Coordinates2EQUAL157EQUALReactome DB_ID: 9360141UniProt:O14933 UBE2L6UBE2L6UBE2L6UBCH8FUNCTION Catalyzes the covalent attachment of ubiquitin or ISG15 to other proteins. Functions in the E6/E6-AP-induced ubiquitination of p53/TP53. Promotes ubiquitination and subsequent proteasomal degradation of FLT3.PATHWAY Protein modification; protein ubiquitination.SUBUNIT Interacts with RNF19A, RNF19B and RNF144B. Interacts with FLT3 (tyrosine phosphorylated).TISSUE SPECIFICITY Present in natural killer cells (at protein level).INDUCTION By IFNB1/IFN-beta.PTM ISGylated.SIMILARITY Belongs to the ubiquitin-conjugating enzyme family.UniProtO149331EQUAL153EQUALReactome Database ID Release 751169385Database identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser?DB=gk_current&ID=1169385ReactomeR-HSA-11693851Reactome stable identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser_st_id?ST_ID=R-HSA-1169385.1Converted from EntitySet in ReactomeReactome DB_ID: 11693811ISG15 E3 ligases [cytosol]Converted from EntitySet in Reactome. Each synonym is a name of a PhysicalEntity, and each XREF points to one PhysicalEntityHERC5 [cytosol]ARIH1 [cytosol]UniProtQ9UII4UniProtQ9Y4X5Reactome Database ID Release 751169383Database identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser?DB=gk_current&ID=1169383ReactomeR-HSA-11693831Reactome stable identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser_st_id?ST_ID=R-HSA-1169383.1Reactome DB_ID: 1691431NS1 dimer [cytosol]NS1 dimerReactome DB_ID: 1691182UniProt:P03496 NSNSNSFUNCTION Prevents the establishment of the cellular antiviral state by inhibiting TRIM25-mediated DDX58 ubiquitination, which normally triggers the antiviral transduction signal that leads to the activation of type I IFN genes by transcription factors IRF3 and IRF7. Prevents human EIF2AK2/PKR activation, either by binding double-strand RNA, or by interacting directly with EIF2AK2/PKR. This function may be important at the very beginning of the infection, when NS1 is mainly present in the cytoplasm. Also binds poly(A) and U6 snRNA.FUNCTION Inhibits post-transcriptional processing of cellular pre-mRNA, by binding and inhibiting two cellular proteins that are required for the 3'-end processing of cellular pre-mRNAs: the 30 kDa cleavage and polyadenylation specificity factor/CPSF4 and the poly(A)-binding protein 2/PABPN1. In turn, unprocessed 3' end pre-mRNAs accumulate in the host nucleus and are no longer exported to the cytoplasm. Cellular protein synthesis is thereby shut off very early after virus infection. Viral protein synthesis is not affected by the inhibition of the cellular 3' end processing machinery because the poly(A) tails of viral mRNAs are produced by the viral polymerase through a stuttering mechanism.SUBUNIT Homodimer. Interacts with host TRIM25 (via coiled coil); this interaction specifically inhibits TRIM25 multimerization and TRIM25-mediated DDX58 CARD ubiquitination. Interacts with human EIF2AK2/PKR, CPSF4, IVNS1ABP and PABPN1.DOMAIN The dsRNA-binding region is required for suppression of RNA silencing.PTM Upon interferon induction, ISGylated via host HERC5; this results in the impairment of NS1 interaction with RNA targets due to its inability to form homodimers and to interact with host EIF2AK2/PKR. There are two ISGylated forms: one form is ISGylated at Lys-20, Lys-41, Lys-217, and Lys-219, and another one at Lys-108, Lys-110, and Lys-126, they represent band I and II respectively. Lys-126 and Lys-217 are critical for host antiviral response in vivo.SIMILARITY Belongs to the influenza A viruses NS1 family.Influenza A virusNCBI Taxonomy11320UniProtP03496Reactome Database ID Release 75169143Database identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser?DB=gk_current&ID=169143ReactomeR-FLU-1691434Reactome stable identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser_st_id?ST_ID=R-FLU-169143.4Reactome DB_ID: 1135921ATP(4-) [ChEBI:30616]ATP(4-)Adenosine 5'-triphosphateatpATPChEBI30616Reactome DB_ID: 11693921ISGylated NS1 [cytosol]ISGylated NS1Reactome DB_ID: 93655212EQUAL157EQUALReactome DB_ID: 1691431Reactome Database ID Release 751169392Database identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser?DB=gk_current&ID=1169392ReactomeR-HSA-11693923Reactome stable identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser_st_id?ST_ID=R-HSA-1169392.3Reactome DB_ID: 1112941diphosphoric acid [ChEBI:29888]diphosphoric acidChEBI29888Converted from EntitySet in ReactomeReactome DB_ID: 11693811Reactome DB_ID: 765771adenosine 5'-monophosphate [ChEBI:16027]adenosine 5'-monophosphateChEBI16027Reactome DB_ID: 93601411EQUAL153EQUALPHYSIOL-LEFT-TO-RIGHTACTIVATIONReactome DB_ID: 1169383GO0004842GO molecular functionReactome Database ID Release 751169401Database identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser?DB=gk_current&ID=1169401Reactome Database ID Release 751169395Database identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser?DB=gk_current&ID=1169395ReactomeR-HSA-11693953Reactome stable identifier. Use this URL to connect to the web page of this instance in Reactome: http://www.reactome.org/cgi-bin/eventbrowser_st_id?ST_ID=R-HSA-1169395.320133869Pubmed2010ISG15 conjugation system targets the viral NS1 protein in influenza A virus-infected cellsZhao, CHsiang, TYKuo, RLKrug, RMProc Natl Acad Sci U S A 107:2253-820385878Pubmed2010Herc5 attenuates influenza A virus by catalyzing ISGylation of viral NS1 proteinTang, YZhong, GZhu, LijunLiu, XShan, YFeng, HBu, ZChen, HWang, CJ Immunol 184:5777-9020219937Pubmed2010Species-specific antagonism of host ISGylation by the influenza B virus NS1 proteinVersteeg, GAHale, BGvan Boheemen, SWolff, TLenschow, DJGarcia-Sastre, AJ Virol 84:5423-30