SAP30 Binding Protein (SAP30BP)

The deduced 308-amino acid protein contains a bipartite nuclear localization signal and an LXXXIXXL motif similar to a motif in nuclear receptor corepressor N-CoR (NCOR1). By Northern blot analysis, they detected a 1,350-nucleotide transcript in human embryo fibroblasts infected with HSV-1 but absent from uninfected fibroblasts, and they detected HTRP mRNA in human brain, heart, liver, lung, spleen, and kidney.

Further analysis of HTRP deletion mutants showed that the N-terminal domain prior to amino acid 225 is responsible for specific HTRP-SAP30 binding. In vitro GST pull-down assays and in vivo immunoprecipitation showed that HTRP interacted with at least 3 proteins including SAP30; however, the identity of the additional 2 proteins was not determined.