A junctional cAMP compartment regulates rapid Ca2+ signaling in atrial myocytes

Axial tubule junctions with the sarcoplasmic reticulum control the rapid intracellular Ca2+-induced Ca2+ release that initiates atrial contraction. In atrial myocytes we previously identified a constitutively increased ryanodine receptor (RyR2) phosphorylation at junctional Ca2+ release sites, whereas non-junctional RyR2 clusters were phosphorylated acutely following β-adrenergic stimulation. Here, we hypothesized that the baseline synthesis of 3′,5′-cyclic adenosine monophosphate (cAMP) is constitutively augmented in the axial tubule junctional compartments of atrial myocytes.

Source: Journal of Molecular and Cellular Cardiology - January 13, 2022 Category: Cytology Authors: S ören Brandenburg, Jan Pawlowitz, Vanessa Steckmeister, Hariharan Subramanian, Dennis Uhlenkamp, Marina Scardigli, Mufassra Mushtaq, Saskia I. Amlaz, Tobias Kohl, Jörg W. Wegener, Demetrios A. Arvanitis, Despina Sanoudou, Leonardo Sacconi, Gerd Hasenfu Source Type: research