Fig. 2.

Pre-incubation with a Ca²⁺ chelator attenuated the DOI-mediated elevation of cytosolic Ca²⁺ and TGase-modified Rac1. a Dynamic changes in the fluorescence ratio (340/380 nm) in Fura-2 loaded A1A1v cells. The Ca²⁺ response to exposure to 3 µM DOI was gradually reduced with the increasing concentrations of BAPTA. A representative example of three independent experiments conducted in triplicate is shown. b Upper, cells were pretreated with 20 µM BAPTA or the vehicle for BAPTA (Ve1) for 30 mins, and then stimulated with 3 µM DOI or the vehicle for DOI (Ve2) for 15 mins. TGase-modified Rac1 was detected by IP and IB analysis. BAPTA inhibited the increase in TGase-modified Rac1 in DOI- stimulated cells. Middle and lower, cells lysates from the same experiment were examined on IB with Na⁺/K⁺ATPase and LDH antibodies respectively. There was no significant difference among various treatments. c Quantitation of effects of BAPTA and DOI on TGase-modified Rac1 in three separate experiments. Data shown were the mean IOD±S.E. M., and they were normalized to Ve1- and Ve2- treated cells. Two-way ANOVA followed by Bonferroni test: one asterisk indicated p<0.001 as compared to Ve1- and Ve2- treated cells; one number sign and two number signs indicated p<0.05 and p<0.001 as compared to Ve1- and DOI- treated cells, respectively