IFNAR1

IFNAR1 (interferon alpha/beta receptor 1) is a core subunit of the type I interferon receptor complex and forms a heterodimeric receptor with IFNAR2 to mediate cellular responses to interferon-α and interferon-β^[1]. Upon type I interferon binding, IFNAR1-associated TYK2 and IFNAR2-associated JAK1 are brought into close proximity, triggering activation of the JAK-STAT signaling pathway and transcription of interferon-stimulated genes involved in antiviral and immune regulatory programs^[4]. Mechanistically, phosphorylation of IFNAR1 creates docking sites for STAT proteins, enabling signal propagation from the plasma membrane to the nucleus and coordinating broad interferon-responsive gene expression networks^[2]. In disease and experimental models, altered IFNAR1 signaling influences antiviral immunity, inflammatory responses, and susceptibility to viral infection, making the receptor a widely used model for studying type I interferon biology^[3]. Compared with related receptor subunits, IFNAR1 exists as a single receptor isoform, whereas IFNAR2 undergoes alternative splicing to generate multiple isoforms with distinct signaling capacities, highlighting a key structural and functional distinction within the type I interferon receptor system^[5]. Furthermore, IFNAR1 and IFNAR2 play distinct roles during initiation of type I interferon signaling, supporting receptor-specific regulatory mechanisms that influence downstream STAT activation^[3]. For experimental and therapeutic applications, antagonism of IFNAR1 has been used to suppress excessive type I interferon signaling, whereas receptor activation remains central to studies of antiviral and immune-modulating interferon responses^[7].