Figure 12.

dIgA stimulation of pIgR-725t is restored by coexpression of pIgR-A657 in a PTK-dependent-manner. MDCK cells expressing pIgR-725t alone (A) or coexpressing both pIgR-725t and pIgR-A657 (B) were submitted to the postmicrotubule-depenedent assay presented Figure 1 with or without 1-h pretreatment of the cells with the PTK inhibitor PP1 (10 μM) before biotinylation (stage A). The drug was also present throughout the assay. In the cotransfected clone 96.5% of total pIgR present at the basolateral surface was pIgR-725t, and 3.5% was pIgR-A657, as indicated in parentheses. n = 8; p < 0.001 for +dIgA in B; p > 0.5 for the other samples in A and B.