Figure 6. TRPM7 kinase domain may be targeting STIM proteins.

A, western blot analyses of TRPM7 expression and phosphorylation in tetracycline‐inducible HEK hTRPM7 cells. (1) uninduced cells (M, marker); (2) cells induced with tetracycline (24 h) and cell lysate treated with λ phosphatase; (3) cells induced with tetracycline (24 h); and (4) cells induced with tetracycline and treated with 30 μm NS8593 (24 h) (a representative blot for four independent experiments is shown) (M, marker). B, percentage of hTRPM7 phosphorylation from cells treated with or without NS8593; lane 3 vs. lane 4 in (A). Phosphorylation was normalized to total protein level (HA‐signal) and phosphorylation in untreated cells was set to 100%. C, average [Ca²⁺]_i responses following store depletion by the addition of 5 μm Tg and readdition of 2 mm [Ca²⁺]_o (SOCE) in DT40 B cells Orai1‐KO, Orai2‐KO and STIM2‐KO with 30 μm NS8593 (+NS) or without (ctrl) in the bath solution. Number of cells are shown in the corresponding bar graphs in (D). D, average of Ca²⁺ influx peaks assessed from baseline and obtained from SOCE measurements in (C). Asterisks indicate statistical significance: ^* P < 0.05; ^** P < 0.01; ^*** P < 0.001.