Fig. 1.

Identification and functional characterization of high frequency mutations of EIAV rev in vivo. (a) Amino acid sequence of Rev exon 2. The functional domains required for Rev activity are boxed and include the nuclear-export signal (aa 31–55) and the RNA binding/nuclear localization signals (RRDR and KRRRK). The shaded area indicates a region not essential for Rev nuclear-export activity (Lee et al., 2006). The location and identity of the high frequency amino acid changes introduced into the backbone of R1 cDNA are indicated. (b) The frequency and location of non-consensus amino acids in Rev exon 2, relative to the consensus variant, R1. (c) Rev nuclear-export activity of single amino acid mutants depicted in (a). The results are expressed relative to R1, and represent the mean activity of at least six independent transfections ± standard error. Variants that differed significantly from the activity of R1, according to a Student’s t-test with unequal variances, are indicated by asterisks: *P<0.05, ** P<0.005, ***P<0.0005.