FIGURE 1.
STI1 interaction with PrPC promotes intracellular Ca2+ increase. A and B, Prnp+/+ (A) or Prnp0/0 (B) hippocampal neurons loaded with Fluo-3 AM were treated with STI1 (1 μm) in medium supplemented with (solid lines) or without (dashed line) Ca2+. THG-treated Prnp0/0 neurons show normal levels of intracellular Ca2+ stores. C, Prnp+/+ neurons were treated with an STI1 deletion mutant, STI1Δ230–245, lacking the PrPC binding site. D, relative intracellular Ca2+ levels in Prnp0/0 (white bars) and Prnp+/+ (black bars) neurons treated with STI1 or STI1Δ230–245 in the presence or absence of CaCl2 are indicated. The results represent the mean ± S.E. (error bars) of four independent experiments, and statistical significance was determined by one-way ANOVA and Newman-Keuls post test. *, p < 0.05 compared with controls.