Fig 8.
Cx43 expression and protein interactions in single-CKO and DKO hearts. (A to D) Heart sections from PGflox/flox/β-cateninflox/flox; Cre− (WT) (A), β-cateninflox/flox; Cre+ (βcat CKO) (B), PGflox/flox; Cre+ (PG CKO) (C), and PGflox/flox/β-cateninflox/flox; Cre+ (DKO) (D) mice were immunostained for Cx43 3 months after Tam administration. (E to H) Representative images of isolated cardiomyocytes from WT (E), β-catenin CKO (F), PG CKO (G), and DKO (H) hearts immunostained for Cx43. Quantitative immunofluorescence microscopy was performed on 20 test areas (ICD regions). (I, J) The average size (I) and area fraction (J) occupied by Cx43-containing clusters for each genotype are shown. (K) Heart lysates were immunoprecipitated with anti-N-cadherin antibody and subsequently immunoblotted for PG, β-catenin (βcat), Cx43, and N-cadherin (Ncad). No-antibody IP served as the negative control (−Ab). Note the significant decrease of the N-cadherin/catenin/Cx43 macromolecular complex in the DKO hearts, whereas the single-CKO hearts maintain the multiprotein complex. (L) Heart lysates from WT, β-catenin CKO, PG CKO, and DKO mice were immunoblotted for dephosphorylated Cx43 (dpCx43) and total Cx43. Note the significant increase in dpCx43 in DKO hearts. *, P < 0.05; **, P < 0.01; ***, P < 0.001.