Figure 7.

IgA/G fragmentation is not due to endocytosis. Protoplasts from plants expressing IgA/G were pulse-labeled for 1 h in the indicated volumes of incubation medium and chased for the indicated periods of time. Cells were then homogenated and subjected to immunoprecipitation with anti-IgG antiserum, followed by 6% (w/v) non-reducing SDS-PAGE and fluorography. Numbers on the left indicate molecular mass markers in kD. Only the intact protein and the higher molecular mass fragments are shown.