Figure 6.
Effect of lactacystin on the dissociation of κNS1 from BiP. (A) The pulse–chase experiment was made under the same conditions as in Figure 1. Equal amounts of cells were used for immunoprecipitation of either Ig L chains or BiP. The calculated half-lives and dissociation rates in minutes are shown for comparison. Note that no dissociation rate can be calculated when lactacystin is added. A reprentative experiment is shown. (B) Ig L chain signals were quantified from the above-shown autoradiograms, and the signals at chase point 0 were set to 100. Note that the two curves obtained for κNS1 chains in the presence of lactacystin differ, depending on whether the Ig L chains were directly precipitated or coprecipitated with BiP. (C) The percentages of κNS1 chains coprecipitated with BiP were calculated at 0 and 2 h of chase. These data represent the mean from seven independent experiments. At each time, the value obtained at 0 h in the control situation (DMSO-0 h) was set to 1.