Transcriptional regulation of intermolecular Ca²⁺ signaling in hibernating ground squirrel cardiomyocytes: The myocardin-junctophilin axis.

ABSTRACT: The contraction of heart cells is controlled by the intermolecular signaling between L-type Ca²⁺ channels (LCCs) and ryanodine receptors (RyRs), and the nanodistance between them depends on the interaction between junctophilin-2 (JPH2) in the sarcoplasmic reticulum (SR) and caveolin-3 (CAV3) in the transversal tubule (TT). In heart failure, decreased expression of JPH2 compromises LCC-RyR communication leading to deficient blood-pumping power. In the present study, we found that JPH2 and CAV3 transcription was concurrently regulated by serum response factor (SRF) and myocardin. In cardiomyocytes from torpid ground squirrels, compared with those from euthermic counterparts, myocardin expression was up-regulated, which boosted both JPH2 and CAV3 expression. Transmission electron m

SUBMITTER: Yang L 

PROVIDER: S-EPMC8040632 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature