JNK2, a Newly-Identified SERCA2 Enhancer, Augments an Arrhythmic [Ca²⁺]_SR Leak-Load Relationship.

ABSTRACT:

Rationale

We recently discovered pivotal contributions of stress kinase JNK2 (c-Jun N-terminal kinase isoform 2) in increased risk of atrial fibrillation through enhanced diastolic sarcoplasmic reticulum (SR) calcium (Ca²⁺) leak via RyR2 (ryanodine receptor isoform 2). However, the role of JNK2 in the function of the SERCA2 (SR Ca²⁺-ATPase), essential in maintaining SR Ca²⁺ content cycling during each heartbeat, is completely unknown.

Objective

To test the hypothesis that JNK2 increases SERCA2 activity SR Ca²⁺ content and exacerbates an arrhythmic SR Ca²⁺ content leak-load relationship.

Methods and results

We used confocal Ca²⁺ imaging in myocytes and HEK-RyR2 (ryanodine receptor isoform 2-expressing hu

SUBMITTER: Yan J 

PROVIDER: S-EPMC7897290 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature