Activation of endogenous protein phosphatase 1 enhances the calcium sensitivity of the ryanodine receptor type 2 in murine ventricular cardiomyocytes.
KEY POINTS Increased protein phosphatase 1 (PP-1) activity was found in the late stages of human heart failure. Although PP-1 has been studied extensively, a detailed understanding of its role in excitation-contraction coupling mechanism, in normal and diseased heart, remains elusive. This work examines the functional effects of the activities of PP-1 on the release of Ca2 + local events in ventricular cardiomyocytes, using the activation peptide (PDP3) for the stimulation of endogenous PP-1 protein. We reported that the acute de-phosphorylation may increase the sensitivity of RyR2 to Ca2 + channels in situ, and that RyR2-serine2808 phosphorylation sites can mediate the process. Our approach unmask the functional importance of PP-1 in the regulation of RyR2 activity, suggesting a potential role in the generation of the pathophysiology of the sarcoplasmic reticulum Ca2 + leak at the heart sick.
ABSTRACT Changes heart Ryanodine receptor (RyR2) phosphorylation was considered a disease of regulation and post-translational modification of proteins related matters. The extent of phosphorylation of RyR2 is mainly determined by the balance of the activity of protein kinases and phosphatases, respectively. Increased protein phosphatase-1 (PP-1) activity has been observed in heart failure, but the role of this enzyme in the regulation of intracellular Ca2 + handling the remains poorly understood.
To determine the physiological and significance of the pathophysiology of increased activity of PP-1, we investigate how the PP-1 catalytic subunit (PP-1c) alter Ca2 + sparks in cardiomyocytes permeabilized and we also apply PP-1-disturbing peptide (PDP3) to specifically activate endogenous PP-1, including one anchored in the RyR2 macromolecular complex.
We compared the wild type (WT) and transgenic mice in which the normally highly phosphorylated RyR2 site-S2808 has been ablated to investigate his involvement in RyR2 modulation (S2808A + / +). In WT myocytes, PP-1 increased the frequency of Ca2 + spark (CaSpF) by 2-fold, followed by depletion of sarcoplasmic reticulum (SR) Ca2 + stores. Similarly, PDP3 temporarily increase and decrease the frequency spark SR Ca2 + load. RyR2 Ca2 + sensitivity, as assessed by analysis of Ca2 + spark recovery, increase with PDP3 when compared to the negative control peptide. S2808A + / + cardiomyocytes do not respond well PP-1c and treatment PDP3.
Our results showed an increase in Ca 2+ sensitivity of RyR2 in the de-phosphorylation by PP-1. Furthermore, we confirmed the S2808 as a target site for PP-1 and as a potential relationship between the modulation RyR2s and cellular responses. This article is protected by copyright. All rights reserved.
Activation of endogenous proteinphosphatase1 enhances the calcium sensitivity of the ryanodine receptor type 2 in murine ventricular cardiomyocytes.
Phactr one set Slack (KCNT one ) channels through protein phosphatase one (PP one ).
The Slack (KCNT1) gene encodes sodium-activated potassium channels are abundant expressed in the central nervous system. human mutations alter channel function Slack, resulting in epilepsy and intellectual disability. The majority of disease-causing mutations located in the cytoplasmic C-terminus extended channels and the result is increased current Slack Slack. Previous experiments have shown that the C-terminus of the protein channel Slack bind a number of cytoplasmic signaling.
Description: A polyclonal antibody against PPP3R1. Recognizes PPP3R1 from Human, Mouse, Rat. This antibody is Unconjugated. Tested in the following application: ELISA, WB, IHC
Description: A polyclonal antibody against PPP3R1. Recognizes PPP3R1 from Human. This antibody is Unconjugated. Tested in the following application: ELISA, WB; Recommended dilution: WB:1:500-1:2000
One is Phactr1, actin-binding protein that recruits protein phosphatase 1 (PP1) to specific phosphoprotein substrates. Using co-immunoprecipitation, we found that Phactr1 required to connect the channel to actin. Using a clamp recordings, we found that co-expression of wild-type channels Phactr1 with Slack reduce current amplitude but had no effect on the channel Slack where preserved PKC phosphorylation sites (S407), which regulates the current amplitude has been mutated.
