Table of Contents - *107450
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Genome
DNA
Protein
Gene Info
Variation
Animal Models
Cellular Pathways
| *107450 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| INTERFERON, ALPHA, BETA, AND OMEGA, RECEPTOR 1; IFNAR1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Alternative titles; symbols | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| IFNAR ANTIVIRAL PROTEIN, ALPHA TYPE; AVP ANTIVIRAL PROTEIN, BETA TYPE INTERFERON, ALPHA, RECEPTOR IFRC INTERFERON, BETA, RECEPTOR; IFNBR | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HGNC Approved Gene Symbol: IFNAR1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Cytogenetic location: 21q22.11 Genomic coordinates (GRCh37): 21:34,697,213 - 34,732,128 (from NCBI) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Cloning | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Novick et al. (1994) described a universal ligand-binding receptor for human interferons alpha and interferon beta. Sarkar and Gupta (1984) showed that gamma-interferon binds to a separate receptor that is carried by WISH cells (a human amnion cell line). The gene for the receptor was designated also IFNAR. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Gene Structure | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lutfalla et al. (1992) detected 11 exons in the IFNAR gene. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Mapping | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Alpha-type antiviral protein is a factor that mediates specific interferon inhibition of virus replication. According to studies of mouse-man hybrid clones, the locus determining this protein is carried on chromosome 21 (Tan et al., 1973). Tan et al. (1974) made observations of dosage effect in monosomy-21 and trisomy-21 cells, which supported assignment of the locus to chromosome 21. This character was also called interferon sensitivity (IS). Chany et al. (1975) showed that trisomy-21 cells have increased interferon sensitivity. Trisomy-16 cells have reduced sensitivity. This might suggest the presence on chromosome 16 of a regulator of mouse antiviral protein. In trisomy-21 fibroblasts, Epstein and Epstein (1976) demonstrated an exaggerated response to both classic (virus-induced) and immune (phytohemagglutinin-induced) forms of interferon. This suggested that despite their physical and antigenic differences the antiviral expression of the 2 interferons is mediated by the same genetic locus. A line trisomic for the distal part of the long arm 21q21-qter also demonstrated increased response, indicating that the AVP gene is located on this part of chromosome 21. Lin et al. (1980) demonstrated that the genes for soluble SOD (147450) and interferon sensitivity are syntenic in the mouse and on chromosome 16. Raziuddin et al. (1984) showed that the receptors for alpha- and beta-interferons are specified by chromosome 21. It was presumed that separate genes encoded the alpha- and beta-interferon receptors. Langer et al. (1990) sublocalized the IFNAR gene to 21q22.1-q22.2 by hybridization of (32)P-labeled recombinant interferon-alpha/beta receptor with human-hamster somatic cell hybrids containing various fragments of human chromosome 21. By in situ hybridization, Lutfalla et al. (1990) refined the assignment to 21q22.1. Lutfalla et al. (1992) further refined the localization by pulsed field gel electrophoresis and its linkage to adjacent markers. They compared the exon structure of the IFNAR gene with that of the genes for receptors of the cytokine/growth hormone/prolactin/interferon receptor family and concluded that they have a common origin and have diverged from the immunoglobulin superfamily with which they share a common ancestor. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Gene Function | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Revel et al. (1976) showed that antibody to a cell surface component coded by human chromosome 21 inhibited the action of interferon. This suggested that antiviral protein is an interferon receptor. See 147570, 147640, 147660 for a discussion of the gamma, beta, and alpha interferons, respectively. De Clercq et al. (1976) concluded that it is not a cell membrane receptor for interferon that is encoded by chromosome 21. Cellular responses to cytokines involve cross-communication through their respective receptors (summary by Takaoka et al., 2000). The IFNs alpha, beta, and gamma mediate innate immune responses to viral infection through IFNAR1/IFNAR2 (602376) for IFNA and IFNB, and IFNGR1 (107470)/IFNGR2 (147569) for IFNG. Stimulation of these receptors activates Janus protein kinases (e.g., JAK1, 147795 and JAK2, 147796), which leads to the tyrosine phosphorylation of STAT1 (600555) and STAT2 (600556). Although the IFN receptors are expressed at low levels in cells, they may be clustered in the cell membrane to permit efficient signal transduction. Using mouse embryonic fibroblasts (MEFs) from IFNAR1- and IFNGR1-deficient mice, Takaoka et al. (2000) observed that the STAT1-mediated DNA-binding activity and the antiviral response to IFNG in IFNAR-null MEFs but not to IFNA in IFNGR-null MEFs are impaired. Restoration of the IFNG response requires constitutive subthreshold IFNA/IFNB signaling and an intact IFNAR1 capable of interacting with STAT1 after tyrosine phosphorylation. Immunoblot analysis showed that IFNAR1 coimmunoprecipitated with the nonligand-binding component, IFNGR2, of the IFNGR complex in wildtype MEFs but less well in IFNB-null MEFs. Immunoblot analysis also demonstrated that the IFN receptor components are exclusively localized in the caveolar membrane fractions (see CAV1; 601047) where there is a concentration of cytoplasmically oriented signaling molecules. In the type I interferon receptor, TYK2 (176941) associates with the IFNAR1 receptor subunit and positively influences ligand binding to the receptor complex. Ragimbeau et al. (2003) found that TYK2 was required for stable cell surface expression of IFNAR1 in human fibrosarcoma cells. In the absence of TYK2, IFNAR1 was exported to the plasma membrane but then accumulated in endocytic organelles. TYK2 coexpression prevented intracellular accumulation of IFNAR1 by restraining its constitutive internalization, and thus stabilized it at the cell surface. Essers et al. (2009) showed that in response to treatment of mice with Ifn-alpha, hematopoietic stem cells (HSCs) efficiently exit G0 and enter an active cell cycle. HSCs respond to Ifn-alpha treatment by the increased phosphorylation of Stat1 (600555) and Akt1 (164730), the expression of Ifn-alpha target genes, and the upregulation of stem cell antigen-1 (Sca1, also known as Ly6a, present only in mouse). HSCs lacking the Ifn-alpha/beta receptor (Ifnar), Stat1, or Sca1 are insensitive to Ifn-alpha stimulation, demonstrating that Stat1 and Sca1 mediate Ifn-alpha-induced HSC proliferation. Although dormant HSCs are resistant to the antiproliferative chemotherapeutic agent 5-fluoro-uracil, HSCs pretreated (primed) with Ifn-alpha and thus induced to proliferate are efficiently eliminated by 5-fluoro-uracil exposure in vivo. Conversely, HSCs chronically activated by Ifn-alpha are functionally compromised and are rapidly outcompeted by nonactivatable Ifnar-null cells in competitive repopulation assays. Whereas chronic activation of the Ifn-alpha pathway in HSCs impairs their function, acute Ifn-alpha treatment promotes the proliferation of dormant HSCs in vivo. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Animal Model | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Listeria monocytogenes (Lm) induces a cytosolic signaling cascade that results in expression of IFNB, a cytokine critical in viral defense. Auerbuch et al. (2004) found that Ifnar1-deficient mice were much more resistant to Lm infection than wildtype mice, suggesting that induction of Ifnb during Lm intracytosolic growth leads to enhanced bacterial survival. Resistance to Lm infection in Ifnar1-deficient mice was associated with an increase in the number of Cd11b (ITGAM; 120980)-positive cells producing Tnf (191160). Auerbuch et al. (2004) proposed that intracytosolic Lm induces Ifnb expression, thereby suppressing Tnf-producing phagocytic cells at sites of bacterial growth. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| See Also: | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Cox et al. (1980); Faltynek et al. (1983); Fournier et al. (1985); Maroun (1980); Slate and Ruddle (1978); Slate et al. (1978); Tan (1976); Weil et al. (1983); Wiranowska-Stewart and Stewart (1977) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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