Monoclonal antibodies against PKCγ and Cav-1 were obtained from BD Biosciences (Palo Alto, CA); monoclonal mouse anti-Cx50 (amino acids 290–440) from Zymed Laboratories (South San Francisco, CA); polyclonal rabbit anti-phosphothreonine (pT) and anti-phosphoserine (pS) from Chemicon (Temecula, CA); polyclonal rabbit anti-Cx46 from Alpha Diagnostic International., Inc. (San Antonio, TX); nonspecific rabbit IgG and protein-agarose beads (A/G PLUS) from Santa Cruz Biotechnology (Santa Cruz, CA); anti-mouse or anti-rabbit IgG conjugated with horseradish peroxidase (HRP), and nonradioactive PKC assay system (PepTag) from Promega (Madison, WI); Dulbecco’s modified Eagle’s medium (DMEM; low glucose), gentamicin, and penicillin-streptomycin from Invitrogen-Life Technologies (Carlsbad, CA); sodium fluoride (NaF) from Fisher Scientific (Pittsburgh, PA); phenylmethylsulfonyl fluoride (PMSF) and protease inhibitor cocktail from Sigma-Aldrich (St. Louis, MO); optimal cutting temperature (OCT) compound from Sakura Finetec (Torrance, CA); Alexa Fluor 568 goat anti-rabbit IgG (H+L), Lucifer yellow, rhodamine dextran, and antifade medium (SlowFade) from Molecular Probes (Eugene, OR); and TPA and PDD from CalBiochem (San Diego, CA).