Fig. 4.

Shrinkage-induced inactivation of S742E and S747E mutant channels coexpressed with functional GCK-3. Cells were swollen for 3 min in hypotonic bath and then shrunken by exposure to a 400 mosM solution. A: time course of shrinkage-induced inactivation of S742E and S747E mutants following 3 min of cell swelling. B: initial rates of shrinkage-induced inactivation of S742E and S747E mutants in the presence or absence of 100 nM calyculin A. Cells were swollen for 1 min without calyculin A and then the drug was added to the bath media for the remainder of the experiment. Values are means ± SE (n = 5–6). *P < 0.01, **P < 0.0001 compared with the S742E mutant.