Figure 3.

ER to cis-Golgi transport is accelerated by the cytoplasmic domain of Emp24p. (A) Autoradiograms of the pulse–chase experiments. The cells expressing the indicated reporters were pulse labeled with [³⁵S]methionine for 2 min and then chased for 5 min. Extracts were prepared at 0 and 5 min after the chase and immunoprecipitated with anti-invertase antibodies. The bound proteins were eluted, separated into two equal aliquots, and immunoprecipitated again with anti-invertase antibodies (Inv) or with anti-α1,6-mannose antibodies (α1,6). Proteins were eluted, treated with Endo H, and analyzed by SDS-PAGE followed by autoradiography. Arrows on the left indicate the full-length form. (B) Rate constants of transport from the ER to the cis-Golgi. The rate constants (k_v) were calculated as described in MATERIALS AND METHODS. Bars, mean values; error bars, SD. The numbers of experiments are shown on top of the bars.