Abstract
Aim: The β1-adrenergic receptor (AR) Arg389Gly polymorphism affects efficacy of its procontractile signaling in cardiomyocytes and carriers’ responses to β-blockers. To identify molecular mechanisms underlying functional differences between Arg389 and Gly389 β1ARs, we examined their binding to β-arrestins (βarr-1 and -2), which mediate β1AR signaling, in neonatal rat ventricular myocytes. Methods: We tested the β1AR–βarr interaction via β1AR immunoprecipitation followed by βarr immunoblotting. Results: βarr1 binds both variants upon isoproterenol, carvedilol or metoprolol treatment in neonatal rat ventricular myocytes. Conversely, the potentially beneficial in the heart βarr2 only interacts with the Arg389 receptor in response to isoproterenol or carvedilol. Conclusion: Arg389 confers unique βarr2-interacting tropism to the β1AR in cardiac myocytes, potentially underlying this variant’s gain-of-function phenotype and better clinical responses to β-blockers.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.
Ethical conduct of research
The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.