Protein phosphatase 2A regulatory subunit B56α limits phosphatase activity in the heart

• DOI: 10.1126/scisignal.aaa5876
• Publication Date: 2015-07-21T18:44:50Z
• Authors: Sean C. Little; Jerry Curran; Michael A. Makara; Crystal F. Kline; Hsiang-Ting Ho; Zhaobin Xu; Xiangqiong Wu; Iuliia Polina; Hassan Musa; Allison M. Meadows; Cynthia A. Carnes; Brandon J. Biesia...; Jonathan P. Davis; Noah Weisleder; Sandor Györke; Xander H. Wehrens; Thomas J. Hund; Peter J. Mohler
• Keywords: Dephosphorylation; Cav1.2

Protein phosphatase 2A (PP2A) is a serine/threonine-selective holoenzyme composed of catalytic, scaffolding, and regulatory subunit. In the heart, PP2A activity requisite for cardiac excitation-contraction coupling central in adrenergic signaling. We found that mice deficient subunit B56α (1 13 subunits) had altered signaling heart was associated with changes physiology, suggesting an autoinhibitory role suppressed excess activity. The increase reduced expression resulted slower rates increased rate variability, conduction defects, sensitivity to parasympathetic agonists. Increased B56α(+/-) myocytes Ca(2+) waves sparks, which decreased phosphorylation (and thus activation) ryanodine receptor RyR2, ion channel on intracellular membranes involved regulation cardiomyocytes. line B56α, vivo absence abundance other subunits basal Consequently, RyR2 These data show integral component has important inhibitory controlling enzyme heart.