Fig. 5.

OR51E1 signaling in CMs. a Detection of transcripts of OR-signaling pathway components, including Gα_olf (GNAL), adenylyl cyclase III (ADCY3) and CNG channel subunits (CNGA2, CNGA4 and CNGB1) in ventricle and septum of explanted human heart and iCell^®-CMs by RT-PCR. b Verification of Gα_olf protein and AC-III expression in human heart tissue by western blot. The molecular size of the two splice variants of Gα_s/olf are 45 kDa (short form; Gα_s/olf-S) and 52 kDa (long form; Gα_s/olf-L). The 39 kDa band (Gα_s/olf-P) may represent the proteolytic fragment of Gα_s/olf [35]. c Co-immunoprecipitations of different G protein alpha-subunits (Gα_s/olf, Gα_q, Gα_i) with OR51E1 protein. The human heart lysate was immunoprecipitated (IP) with one of the indicated G proteins and detected with antibodies against the OR51E1 protein. d Representative recordings of Fura-2 loaded iCell^®-CMs. Co-application of nonanoic acid (500 µM) and inhibitor gallein (10 µM). e Quantification of nonanoic acid-induced negative chronotropic effects by pretreating with or without gallein (10 µM) in Ca²⁺ imaging experiments. The data are shown as the mean ± SEM (n > 40). Significance was calculated Student’s t test or Mann–Whitney U test (*p < 0.05, **p < 0.01 and ***p < 0.001)