Plays a role in the inhibition of host innate immunity by inducing the degradation of key host factors required to activate interferon production such as IRF3, IRF5 or IRF7. Associates with components of cullin RING ligases (CRLs) including CUL1 or CUL3, which are essential multisubunit ubiquitination complexes, to modulate their activities. Interacts (via C-terminus) with host IRF3; this interaction leads to IRF3 degradation. Interacts with host IRF7; this interaction leads to IRF7 degradation. Interacts with host CUL1 and CUL3. The integrity of the zinc-binding domain in NSP1 is important for degradation of host IRF3. Belongs to the rotavirus NSP1 family.