Interferon regulatory factor 3 is a cellular partner of rotavirus NSP1.
The rotavirus nonstructural protein NSP1 is the least conserved protein in the rotavirus genome, and its function in the replication cycle is not known. We employed NSP1 as bait in the yeast two-hybrid interaction trap to identify candidate cellular partners of NSP1 that may provide clues to its function. Interferon regulatory factor 3 (IRF-3) was identified as an NSP1 interactor. NSP1 synthesized in rotavirus-infected cells bound IRF-3 in a glutathione S-transferase pull-down assay, indicating that the interaction was not unique to the two-hybrid system. NSP1 of murine rotavirus strain EW also interacted with IRF-3. NSP1 deletion and point mutants were constructed to map domains important in the interaction between NSP1 and IRF-3. The data suggest that a binding domain resides in the C terminus of NSP1 and that the N-terminal conserved zinc finger is important but not sufficient to mediate binding to IRF-3. We predict that a role for NSP1 in rotavirus-infected cells is to inhibit activation of IRF-3 and diminish the cellular interferon response.
Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717, USA.
Joel W
JW
Graff
Dana N
DN
Mitzel
Carla M
CM
Weisend
Michelle L
ML
Flenniken
Michele E
ME
Hardy
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D050838:Interferon Regulatory Factor-3; D008969:Molecular Sequence Data; D009154:Mutation; D012401:Rotavirus / Q000472:pathogenicity*; D012400:Rotavirus Infections / Q000821:virology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; C494232:IRF3 protein, human; D050838:Interferon Regulatory Factor-3; D014157:Transcription Factors; D017361:Viral Nonstructural Proteins; C104282:nsp1 protein, Rotavirus; D005982:Glutathione Transferase