FRET biosensor uncovers cAMP nano-domains at β-adrenergic targets that dictate precise tuning of cardiac contractility

Nat Commun. 2017 Apr 20;8:15031. doi: 10.1038/ncomms15031.

Abstract

Compartmentalized cAMP/PKA signalling is now recognized as important for physiology and pathophysiology, yet a detailed understanding of the properties, regulation and function of local cAMP/PKA signals is lacking. Here we present a fluorescence resonance energy transfer (FRET)-based sensor, CUTie, which detects compartmentalized cAMP with unprecedented accuracy. CUTie, targeted to specific multiprotein complexes at discrete plasmalemmal, sarcoplasmic reticular and myofilament sites, reveals differential kinetics and amplitudes of localized cAMP signals. This nanoscopic heterogeneity of cAMP signals is necessary to optimize cardiac contractility upon adrenergic activation. At low adrenergic levels, and those mimicking heart failure, differential local cAMP responses are exacerbated, with near abolition of cAMP signalling at certain locations. This work provides tools and fundamental mechanistic insights into subcellular adrenergic signalling in normal and pathological cardiac function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-Agonists / pharmacology
  • Amino Acid Sequence
  • Animals
  • Biosensing Techniques / methods*
  • CHO Cells
  • Cells, Cultured
  • Cricetinae
  • Cricetulus
  • Cyclic AMP / metabolism*
  • Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit / genetics
  • Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit / metabolism
  • Fluorescence Resonance Energy Transfer / methods*
  • Isoproterenol / pharmacology
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Male
  • Myocardial Contraction / drug effects
  • Myocytes, Cardiac / cytology
  • Myocytes, Cardiac / metabolism*
  • Myocytes, Cardiac / physiology
  • Rats, Sprague-Dawley
  • Receptors, Adrenergic, beta / metabolism*
  • Sarcomeres / metabolism
  • Sarcomeres / physiology
  • Sequence Homology, Amino Acid

Substances

  • Adrenergic beta-Agonists
  • Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit
  • Luminescent Proteins
  • Prkar2b protein, rat
  • Receptors, Adrenergic, beta
  • Cyclic AMP
  • Isoproterenol