Mumps Virus SH Protein Inhibits NF-κB Activation by Interacting with Tumor Necrosis Factor Receptor 1, Interleukin-1 Receptor 1, and Toll-Like Receptor 3 Complexes.

The mumps virus (MuV) small hydrophobic protein (SH) is a type I membrane protein expressed in infected cells. SH has been reported to interfere with innate immunity by inhibiting tumor necrosis factor alpha (TNF-α)-mediated apoptosis and NF-κB activation. To elucidate the underlying mechanism, we generated recombinant MuVs (rMuVs) expressing the SH protein with an N-terminal FLAG epitope or lacking SH expression due to the insertion of three stop codons into the gene.

Mumps virus small hydrophobic protein targets ataxin-1 ubiquitin-like interacting protein (ubiquilin 4).

The small hydrophobic (SH) protein of mumps virus has been reported to interfere with innate immunity by inhibiting tumour necrosis factor alpha-mediated apoptosis. In a yeast two-hybrid screen we have identified the ataxin-1 ubiquitin-like interacting protein (A1Up) as a cellular target of the SH protein. A1Up contains an amino-terminal ubiquitin-like (UbL) domain, a carboxy-terminal ubiquitin-associated (UbA) domain and two stress-inducible heat shock chaperonin-binding (Sti1) motifs.