Receptor-transporting protein 4 (RTP4)

Receptor-transporting protein 4 (RTP4) is a cytoplasmic, membrane-associated protein primarily recognized for its role in promoting cell-surface expression of certain G protein-coupled receptors (notably in chemosensory, pain, and olfactory pathways) and as an interferon-stimulated gene involved in host immune defense. RTP4 is rapidly upregulated following type I interferon signaling during viral and parasitic infection. Mechanistically, RTP4 acts as a negative regulator of type I interferon responses by binding to the TANK-binding kinase 1 (TBK1) complex, thereby inhibiting phosphorylation (activation) of TBK1 and interferon-regulatory factor 3 (IRF3), ultimately suppressing the production of type I interferons and several interferon-stimulated genes. Studies in mouse models show that RTP4 modulation has effects on susceptibility to viral brain infections and malaria-induced neurological symptoms, suggesting it is a potential (but currently undrugged) target for immune modulation in infectious and inflammatory diseases.

Other names

28 kDa interferon-responsive protein3CxxC-type zinc finger protein 4IFRG28Z3CXXC4receptor (chemosensory) transporter protein 4zinc finger, 3CxxC-type 4

No direct drugs known. Biological mechanism involves RTP4 binding to TBK1 complex, inhibiting TBK1- and IRF3-mediated signaling, thereby dampening IFN-I production and interferon-stimulated gene response