Substrate-specific adapter of SKP1-containing E3 ubiquitin-protein ligases which mediate the ubiquitination and subsequent proteasomal degradation of host target proteins. Prevents activation and subsequent nuclear localization of NF-kappa-B in infected cells, by targeting NF-kappa-B RELA subunit to the SCF E3 ligase complex. Interacts (via N-terminus) with host RELA. Interacts (via PRANC/F-box-like domain) with the SKP1 component of the host SCF ubiquitin ligase complex.