Figure 7.

The isoleucine residue in the linker peptide is required for vacuolar sorting. A, Effect of the I271G on the intracellular fate of proricin. Cells were transfected with ppricin or ppricin I271G, pulse labeled for 1 h, and chased for the indicated periods of time. Cell homogenates and incubation media were immunoprecipitated with anti-RTA antiserum and analyzed by SDS-PAGE and fluorography. White arrowheads indicate the position of proricin and black arrowheads indicate mature RTA and RTB. Numbers at right indicate molecular mass markers in kilodaltons. B, Effect of the I271G mutation on the intracellular fate of the RTA-L/RTB heterodimer. Cells were transfected with the indicated constructs, pulse labeled for 1 h, and chased for the indicated periods of time. Cell homogenates and incubation media were immunoprecipitated with anti-RTA antiserum and analyzed by SDS-PAGE and fluorography.