Impact of β1-adrenoceptor variation in vitro and ex vivo
| Variation | Parameter | Cell/Tissue | Variant Effect | Reference |
|---|---|---|---|---|
| c.145A>G (p.Ser49Gly) | Overexpression in cell lines (studies in vitro) | |||
| Ligand binding affinity | CHW-1102a | Ser = Gly | Rathz et al. (2002) | |
| HEK-293b | Ser = Gly | Rathz et al. (2002) | ||
| HEK-293c | Ser < Gly | Levin et al. (2002) | ||
| HEK-293c | Ser = Gly | Baker et al. (2013) | ||
| Basal/maximal agonist-stimulated AC activity | CHW-1102a | Ser = Gly | Rathz et al. (2002) | |
| HEK-293c | Ser < Gly | Levin et al. (2002) | ||
| Agonist-induced downregulation | HEK-293c | Ser < Gly | Levin et al. (2002) | |
| HEK-293b | Ser < Gly | Rathz et al. (2002) | ||
| Endogenous receptor expression (studies ex vivo) | ||||
| NE-induced increase in contractility | Isolated right atria (CABG) | Molenaar et al. (2002) | ||
| 87 β-blocker treated | Ser = Gly | |||
| 20 without β-blocker | Ser = Gly | |||
| CGP-12177–induced increase in contractility | Isolated right atria (60, nonfailing) | Ser = Gly | Sarsero et al. (2003) | |
| c.1165C>G (p.Arg389Gly) | Overexpression in cell lines (studies in vitro) | |||
| Agonist binding affinity | CHW-1102b | − GTP: Arg > Gly | Mason et al. (1999) | |
| + GTP: Arg = Gly | Joseph et al. (2004) | |||
| CHO-AA8a | Arg = Gly | Rochais et al. (2007) | ||
| HEK-293c | Arg = Gly | |||
| HEK-293c | Arg = Gly | Baker et al. (2013) | ||
| Ligand-induced conformational changes | HEK-293c | Bisoprolol/metoprolol: Arg = Gly | Rochais et al. (2007) | |
| Carvedilol: Arg > Gly | ||||
| G protein activation | COS-7c | Arg > Gly | Mason et al. (1999) | |
| HEK-293c | Arg = Gly | Rochais et al. (2007) | ||
| Basal/maximal agonist-stimulated AC activity cAMP formation | CHW-1102b | Arg > Gly | Mason et al. (1999) | |
| CHO-AA8a | Arg > Gly | Joseph et al. (2004) | ||
| HEK-293c | Arg > Gly | Zhang and Steinberg, 2013) | ||
| MAPK activation | HEK-293c | Arg > Gly | Zhang and Steinberg, 2013) | |
| Beating frequency | NRCM | Arg > Gly | Rochais et al. (2007) | |
| Endogenous receptor expression (studies ex vivo) | ||||
| High-affinity ligand binding | Membranes from nonfailing left ventricle (17) | Arg > Gly carriers | O’Connor et al. (2012) | |
| Agonist-induced increase in contractility | Isolated right atria (CABG) | Molenaar et al. (2002) | ||
| 87 β-blocker treated | Arg = Gly | |||
| 20 without β-blocker | Arg = Gly | |||
| Isolated right atria (54, CABG, AVR, or MVR) | Arg > Gly | Sandilands et al. (2003) | ||
| Isolated right ventricular trabeculae | Liggett et al. (2006) | |||
| 22 nonfailing | Arg > Gly carriers | |||
| 31 failing (end-stage HF) | Arg > Gly carriers | |||
| CGP-12177–induced increase in contractility | Isolated right atria (61, nonfailing) | Arg = Gly | Sarsero et al. (2003) |
AC, adenylyl cyclase; AVR, aortic valve replacement; CABG, coronary artery bypass graft; HF, heart failure; MVR, mitral valve replacement; NE, norepinephrine; NRCM, neonatal rat cardiac myocyte.
↵a Receptor expression: ≤0.2 pmol/mg.
↵b Receptor expression: >0.2 and <0.5 pmol/mg.
↵c Receptor expression: ≥0.5 pmol/mg membrane protein.