FIGURE 8.

Interaction of HTLV-1 wt and late domain mutants with WW domains of Nedd4, WWP1, ITCH, and SMURF-1. A, pM-p19 wt and the related late domain mutant plasmids express the Gal4 DNA-binding domain fused to residues 5–154 of Gag. The pVP16-WW plasmids express fusions between the WW domains of the indicated UL and the VP16 activation domain. The reporter plasmid pGL5-Luc expresses the luciferase gene under control of five copies of the Gal4 consensus binding site. Average of three experiments with standard deviations is shown. Activation is expressed as the fold-induction over that seen with the pM-p19 and the parental pVP16 plasmid, values were corrected for the expression level of the WW chimeras as determined by image analysis as shown in C. B, VP16-SMURF-1WW can bind Gal4DB-SMAD1PR. The SMAD PR region encodes residues 133–266, which have previously been shown to interact with the WW domain of SMURF-1. C, anti-VP16 immunoblot showing expression of the VP16-WW domains of the indicated ULs.