NSP1 (NS53), the product ofrotavirus gene 5, is anonstructural RNA-binding protein that contains a cysteine-rich region and is a component of early replication intermediates. RNA-folding predictions suggest that this region of the NSP1mRNA can interact with itself, producing a stem-loop structure similar to that found near the 5'-terminus of the NSP1mRNA.[1]
The carboxyl-half of therotavirus nonstructural protein NSP1 is not required for virus replication.[2]
NSP1 could play a role in host range restriction.[3]
The cysteine-rich region of NSP1 is not considered essential for genome segment reassortment with heterologous virus.[4]
NSP1 interacts withIRF3 in the infected cell. NSP1 is an antagonist of the IFN-signaling pathway.[5]
Interferon regulatory factor 3 (IRF3) is a key transcription factor involved in the induction of interferon (IFN) in response to viral infection. NSP1 binds to and targets IRF3 forproteasome degradation early post-infection. IRF3 degradation is dependent on the presence of NSP1 and the integrity of the N-terminal zinc-binding domain, coupled with the regulated stability of IRF3 and NSP1 by the proteasome, collectively support the hypothesis that NSP1 is an E3 ubiquitin ligase.[6]
NSP1 could mediates the degradation ofIRF3,IRF5, andIRF7 by recognizing a common element of IRF proteins, thereby allowing NSP1 to act as a broad-spectrum antagonist of IRF function.[7]
NSP1 inhibits cellular apoptosis by directly interacting p85 subunit of PI3K and thus activating PI3K/Akt survival pathway during early stages of rotavirus infection.[9][10]
^Okada J, Kobayashi N, Taniguchi K, Urasawa S (1999). "Analysis on reassortment of rotavirus NSP1 genes lacking coding region for cysteine-rich zinc finger motif".Archives of Virology.144 (2):345–53.doi:10.1007/s007050050508.PMID10470258.S2CID13288814.
