Cargando…

Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells

Spontaneous AP (action potential) firing of sinoatrial nodal cells (SANC) is critically dependent on protein kinase A (PKA) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII)-dependent protein phosphorylation, which are required for the generation of spontaneous, diastolic local Ca(2+) relea...

Descripción completa

Detalles Bibliográficos
Autores principales: Sirenko, Syevda Tagirova, Zahanich, Ihor, Li, Yue, Lukyanenko, Yevgeniya O., Lyashkov, Alexey E., Ziman, Bruce D., Tarasov, Kirill V., Younes, Antoine, Riordon, Daniel R., Tarasova, Yelena S., Yang, Dongmei, Vinogradova, Tatiana M., Maltsev, Victor A., Lakatta, Edward G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8623309/
https://www.ncbi.nlm.nih.gov/pubmed/34831329
http://dx.doi.org/10.3390/cells10113106
_version_ 1784605902329872384
author Sirenko, Syevda Tagirova
Zahanich, Ihor
Li, Yue
Lukyanenko, Yevgeniya O.
Lyashkov, Alexey E.
Ziman, Bruce D.
Tarasov, Kirill V.
Younes, Antoine
Riordon, Daniel R.
Tarasova, Yelena S.
Yang, Dongmei
Vinogradova, Tatiana M.
Maltsev, Victor A.
Lakatta, Edward G.
author_facet Sirenko, Syevda Tagirova
Zahanich, Ihor
Li, Yue
Lukyanenko, Yevgeniya O.
Lyashkov, Alexey E.
Ziman, Bruce D.
Tarasov, Kirill V.
Younes, Antoine
Riordon, Daniel R.
Tarasova, Yelena S.
Yang, Dongmei
Vinogradova, Tatiana M.
Maltsev, Victor A.
Lakatta, Edward G.
author_sort Sirenko, Syevda Tagirova
collection PubMed
description Spontaneous AP (action potential) firing of sinoatrial nodal cells (SANC) is critically dependent on protein kinase A (PKA) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII)-dependent protein phosphorylation, which are required for the generation of spontaneous, diastolic local Ca(2+) releases (LCRs). Although phosphoprotein phosphatases (PP) regulate protein phosphorylation, the expression level of PPs and phosphatase inhibitors in SANC and the impact of phosphatase inhibition on the spontaneous LCRs and other players of the oscillatory coupled-clock system is unknown. Here, we show that rabbit SANC express both PP1, PP2A, and endogenous PP inhibitors I-1 (PPI-1), dopamine and cyclic adenosine 3′,5′-monophosphate (cAMP)-regulated phosphoprotein (DARPP-32), kinase C-enhanced PP1 inhibitor (KEPI). Application of Calyculin A, (CyA), a PPs inhibitor, to intact, freshly isolated single SANC: (1) significantly increased phospholamban (PLB) phosphorylation (by 2–3-fold) at both CaMKII-dependent Thr(17) and PKA-dependent Ser(16) sites, in a time and concentration dependent manner; (2) increased ryanodine receptor (RyR) phosphorylation at the Ser(2809) site; (3) substantially increased sarcoplasmic reticulum (SR) Ca(2+) load; (4) augmented L-type Ca(2+) current amplitude; (5) augmented LCR’s characteristics and decreased LCR period in intact and permeabilized SANC, and (6) increased the spontaneous basal AP firing rate. In contrast, the selective PP2A inhibitor okadaic acid (100 nmol/L) had no significant effect on spontaneous AP firing, LCR parameters, or PLB phosphorylation. Application of purified PP1 to permeabilized SANC suppressed LCR, whereas purified PP2A had no effect on LCR characteristics. Our numerical model simulations demonstrated that PP inhibition increases AP firing rate via a coupled-clock mechanism, including respective increases in the SR Ca(2+) pumping rate, L-type Ca(2+) current, and Na(+)/Ca(2+)-exchanger current. Thus, PP1 and its endogenous inhibitors modulate the basal spontaneous firing rate of cardiac pacemaker cells by suppressing SR Ca(2+) cycling protein phosphorylation, the SR Ca(2+) load and LCRs, and L-type Ca(2+) current.
format Online
Article
Text
id pubmed-8623309
institution National Center for Biotechnology Information
language English
publishDate 2021
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-86233092021-11-27 Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells Sirenko, Syevda Tagirova Zahanich, Ihor Li, Yue Lukyanenko, Yevgeniya O. Lyashkov, Alexey E. Ziman, Bruce D. Tarasov, Kirill V. Younes, Antoine Riordon, Daniel R. Tarasova, Yelena S. Yang, Dongmei Vinogradova, Tatiana M. Maltsev, Victor A. Lakatta, Edward G. Cells Article Spontaneous AP (action potential) firing of sinoatrial nodal cells (SANC) is critically dependent on protein kinase A (PKA) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII)-dependent protein phosphorylation, which are required for the generation of spontaneous, diastolic local Ca(2+) releases (LCRs). Although phosphoprotein phosphatases (PP) regulate protein phosphorylation, the expression level of PPs and phosphatase inhibitors in SANC and the impact of phosphatase inhibition on the spontaneous LCRs and other players of the oscillatory coupled-clock system is unknown. Here, we show that rabbit SANC express both PP1, PP2A, and endogenous PP inhibitors I-1 (PPI-1), dopamine and cyclic adenosine 3′,5′-monophosphate (cAMP)-regulated phosphoprotein (DARPP-32), kinase C-enhanced PP1 inhibitor (KEPI). Application of Calyculin A, (CyA), a PPs inhibitor, to intact, freshly isolated single SANC: (1) significantly increased phospholamban (PLB) phosphorylation (by 2–3-fold) at both CaMKII-dependent Thr(17) and PKA-dependent Ser(16) sites, in a time and concentration dependent manner; (2) increased ryanodine receptor (RyR) phosphorylation at the Ser(2809) site; (3) substantially increased sarcoplasmic reticulum (SR) Ca(2+) load; (4) augmented L-type Ca(2+) current amplitude; (5) augmented LCR’s characteristics and decreased LCR period in intact and permeabilized SANC, and (6) increased the spontaneous basal AP firing rate. In contrast, the selective PP2A inhibitor okadaic acid (100 nmol/L) had no significant effect on spontaneous AP firing, LCR parameters, or PLB phosphorylation. Application of purified PP1 to permeabilized SANC suppressed LCR, whereas purified PP2A had no effect on LCR characteristics. Our numerical model simulations demonstrated that PP inhibition increases AP firing rate via a coupled-clock mechanism, including respective increases in the SR Ca(2+) pumping rate, L-type Ca(2+) current, and Na(+)/Ca(2+)-exchanger current. Thus, PP1 and its endogenous inhibitors modulate the basal spontaneous firing rate of cardiac pacemaker cells by suppressing SR Ca(2+) cycling protein phosphorylation, the SR Ca(2+) load and LCRs, and L-type Ca(2+) current. MDPI 2021-11-10 /pmc/articles/PMC8623309/ /pubmed/34831329 http://dx.doi.org/10.3390/cells10113106 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Sirenko, Syevda Tagirova
Zahanich, Ihor
Li, Yue
Lukyanenko, Yevgeniya O.
Lyashkov, Alexey E.
Ziman, Bruce D.
Tarasov, Kirill V.
Younes, Antoine
Riordon, Daniel R.
Tarasova, Yelena S.
Yang, Dongmei
Vinogradova, Tatiana M.
Maltsev, Victor A.
Lakatta, Edward G.
Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells
title Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells
title_full Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells
title_fullStr Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells
title_full_unstemmed Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells
title_short Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells
title_sort phosphoprotein phosphatase 1 but not 2a activity modulates coupled-clock mechanisms to impact on intrinsic automaticity of sinoatrial nodal pacemaker cells
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8623309/
https://www.ncbi.nlm.nih.gov/pubmed/34831329
http://dx.doi.org/10.3390/cells10113106
work_keys_str_mv AT sirenkosyevdatagirova phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT zahanichihor phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT liyue phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT lukyanenkoyevgeniyao phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT lyashkovalexeye phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT zimanbruced phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT tarasovkirillv phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT younesantoine phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT riordondanielr phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT tarasovayelenas phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT yangdongmei phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT vinogradovatatianam phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT maltsevvictora phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells
AT lakattaedwardg phosphoproteinphosphatase1butnot2aactivitymodulatescoupledclockmechanismstoimpactonintrinsicautomaticityofsinoatrialnodalpacemakercells