Suppression of Cx43 promoter by calreticulin.

<p>(A) A schematic representation of calreticulin and calreticulin domains. CRT, calreticulin full length tagged with HA epitope; CRT-PC, P+C domain of calreticulin tagged with HA epitope. HA, hemagglutinin; KDEL, ER retrieval amino acid sequence. (B) Western blot analysis with anti-HA antibodies (reporting recombinant calreticulin and calreticulin PC domain) and anti-Cx43 antibodies of cell lysates from H9C2 cells (<i>H9C2</i>), H9C2 cells expression full length calreticulin (<i>H9C2+CRT</i>), and H9C2 cells expression Ca²⁺ buffering PC domain of calreticulin (<i>H9C2+CRT-PC</i>). HA, hemagglutinin; CRT, calreticulin; CRT-PC, calreticulin P+C domain. GAPDH was used as a loading control. (C) Control H9C2 cells (<i>H9C2</i>), H9C2 cell lines expression full length calreticulin (<i>H9C2+CRT</i>) or H9C2 cells expression Ca²⁺ buffering PC domain of calreticulin (<i>H9C2+CRT-PC</i>) were transfected with luciferase reporter vector under control of the Cx43 promoter and β-galactosidase expression vector. Cell lysates were harvested and assayed for luciferase activity. **<i>p</i><0.01 (n = 9).