Effect of GPA on currents induced by hAE1 mutations. Current-voltage curves measured in control oocytes (NI) or injected with mutant hAE1 (H734R or S731P: ◊) or coinjected with mutant hAE1 and human glycophorin A (▲). Oocytes were bathed in MBS. Data presented are mean (± SEM) of 5 oocytes. In some cases, the SEM is smaller than the symbols and thus not visible in the graph. The conductance of oocytes injected with hGPA alone was the same as for NI oocytes.