Figure 4.

NPSN11 and KNOLLE cofractionate on an Accudenz gradient. Total membranes prepared from 21-d-old liquid-cultured Arabidopsis roots were separated by a discontinuous Accudenz gradient. Fractions of 0.5 mL were collected from top to the bottom. The density of each fraction was plotted against the fraction number (A). Fractions were collected, and equal amounts were separated by SDS-PAGE and then blotted with the indicated antisera (B). NPSN11 cofractionated with KNOLLE but not with AtELP, the TGN marker; VTI11, which labels the PVC; or VTI12, which labels both the PVC and the TGN.