Mammalian type I interferon receptors consists of two subunits: IFNaR1 and IFNaR2.
The human type I interferon (IFN) receptor consists of two essential subunits, huIFNaR1 and huIFNaR2; however, so far only IFNaR1 has been identified in other species. Furthermore, it has been suggested that in some species the type I IFN receptor may consist of a single subunit, since expression of murine IFNaR1 in human cells rendered them responsive to several type I murine IFNs. To resolve this issue, we screened a mouse cDNA library with a probe derived from huIFNaR2 cDNA. A cDNA clone, coding for a transmembrane protein which has 49% identity with huIFNaR2 was isolated. This level of identity suggests that this cDNA codes for a muIFNaR2. In addition, several cDNA clones, coding for two distinct soluble variants of muIFNaR2 were identified. To test whether muIFNaR2 is a functional component of the receptor, we co-expressed it with muIFNaR1 in human cells and with an IFN-responsive luciferase reporter vector. Treatment of these cells with muIFN-beta induced high levels of luciferase, whereas no induction was obtained in cells expressing only one of the two subunits. We therefore conclude that the murine type I IFN receptor consists of two different subunits--a configuration shared by humans, and probably all other mammals.
Kim
S H
SH
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
Cohen
B
B
Novick
D
D
Rubinstein
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D006801:Humans; D008322:Mammals / Q000235:genetics*; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D012326:RNA Splicing; D053633:Receptor, Interferon alpha-beta; D017471:Receptors, Interferon / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
C507964:IFNAR1 protein, human; C508033:IFNAR2 protein, human; C508032:Ifnar1 protein, mouse; C508034:Ifnar2 protein, mouse; D008565:Membrane Proteins; D017471:Receptors, Interferon; D053633:Receptor, Interferon alpha-beta