KH and NYN domain-containing protein (KHNYN)

KHNYN (KH and NYN domain-containing protein) is a multidomain endoribonuclease that functions as a cofactor for the zinc finger antiviral protein (ZAP). The protein contains a KH-like domain (which, unlike classical KH domains, does not robustly bind RNA but may interface with other proteins) and a NYN domain that confers catalytic activity required for the degradation of viral RNA. KHNYN is essential for ZAP-mediated antiviral activity and restricts infection by viruses such as HIV and SARS-CoV-2, supporting the cellular antiviral response. Unlike canonical KH domains, the KHNYN KH domain is evolutionarily divergent and primarily serves as a protein-protein interaction site rather than an RNA-binding module. KHNYN is not currently targeted by any drugs, nor used as a biomarker or has known therapeutic safety concerns. Its disease role is mainly related to host defense against viral infection.

Other names

KHNYNKIAA0323Protein KHNYNKH and NYN domain-containing proteinCGIN1 domain-containing protein

Mechanism for biological function involves endonucleolytic cleavage (via NYN domain) and facilitating ZAP-mediated RNA degradation