Figure 7.
ERdj3 mutant interacts with BiP:light chain complex more stably. COS-1 cells were cotransfected with the indicated cDNA clones. Transfectants were labeled with [35S]methionine for 45 min in the presence of DTT, washed, and then chased in complete media devoid of DTT for the indicated times. Cell lysates were divided equally and immunoprecipitated with antisera specific for mouse λ (A), rodent BiP (B), or HA-tagged ERdj3 (HA/J3) (C) and subjected to nonreducing SDS-PAGE. The three light chain folding intermediates are indicated on the left (A). A longer exposure of light chain folding in the λ + BiP + mutant ERdj3 transfectant is shown to the right for comparison with the other transfectants (A).