Figure 2.

touchdown alleles tdo^tz310c, tdo^b508, and tdo^mi174 harbor mutations that abolish channel activity. A, A graphic representation of TRPM7 indicating the location of mutations in the three alleles of touchdown. CC, Coiled-coil domain; STP, serine-threonine-proline rich domain; KD, kinase domain. B, Average current responses of oocytes expressing wild-type TRPM7 or touchdown alleles to voltage ramps between −100 and +60 mV (n = 10 oocytes for each allele) showing that all three alleles lack channel activity (i.e., the currents in response to ramps were not significantly different from those of uninjected oocytes). Values represent the average ± SEM. *p < 0.05, t test.