Evidence map›Paper›PMID 25450489›Full record

ArticleBiochimica et biophysica acta2015

Pathogenesis associated with a restrictive cardiomyopathy mutant in cardiac troponin T is due to reduced protein stability and greatly increased myofilament Ca2+ sensitivity.

Michelle S Parvatiyar, Jose Renato Pinto

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In one paragraph

Article in Biochimica et biophysica acta, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.4field-weighted citation impact, top 33% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 7 citations in OpenAlex.

  1. Article
  2. Variant R94C inJournal of the American Heart Association · 2020
    Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 2 institutions in 1 country.

Michelle S ParvatiyarDepartment of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Jose Renato PintoDepartment of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, USA. Electronic address: jose.pinto@med.fsu.edu.
Florida State University · USUniversity of Miami · US

Funding

The Role of Cardiomyopathic Troponin C Mutations in Skeletal and Cardiac Muscle CR00HL103840 · NHLBI · FLORIDA STATE UNIVERSITY · PI PINTO, JOSE RENATO · 2012 to 2014
$717k
The Role of Cardiomyopathic Troponin C Mutations in Skeletal and Cardiac Muscle CK99HL103840 · NHLBI · UNIVERSITY OF MIAMI SCHOOL OF MEDICINE · PI PINTO, JOSE RENATO · 2010 to 2011
$188k
NHLBI NIH HHS HL103840NHLBI NIH HHS K99 HL103840NHLBI NIH HHS R00 HL103840
6 · The paper itself

Abstract

backgroundDilated and hypertrophic cardiomyopathy mutations in troponin can blunt effects of protein kinase A (PKA) phosphorylation of cardiac troponin I (cTnI), decreasing myofilament Ca2+-sensitivity; however this effect has never been tested for restrictive cardiomyopathy (RCM) mutants. This study explores whether an RCM cardiac troponin T mutant (cTnT-ΔE96) interferes with convergent PKA regulation and if TnT instability contributes to greatly enhanced Ca2+-sensitivity in skinned fibers.

methodsForce of contraction in skinned cardiac porcine fiber and spectroscopic studies were performed.

resultsA decrease of -0.26 and -0.25 pCa units in Ca2+-sensitivity of contraction after PKA incubation was observed for skinned fibers incorporated with WT or cTnT-ΔE96, respectively. To further assess whether cTnT-ΔE96 interferes solely with transmission of cTnI phosphorylation effects, skinned fibers were reconstituted with PKA pseudo-phosphorylated cTnI (cTnI-SS/DD.cTnC). Fibers displaced with cTnT-WT, reconstituted with cTnI-SS/DD.cTnC decreased Ca2+-sensitivity of force (pCa50=5.61) compared to control cTnI-WT.cTnC (pCa50=5.75), similarly affecting cTnT-ΔE96 (pCa50=6.03) compared to control \cTnI-WT.cTnC (pCa50=6.14). Fluorescence studies measuring cTnC(IAANS) Ca2+-affinity changes due to cTnT-ΔE96 indicated that higher complexity (thin filament) better recapitulates skinned fiber Ca2+ sensitive changes. Circular dichroism revealed reduced α-helicity and earlier thermal unfolding for cTnT-ΔE96 compared to WT.

conclusionsAlthough ineffective in decreasing myofilament Ca2+-sensitivity to normal levels, cTnT-ΔE96 does not interfere with PKA cTnI phosphorylation mediated effects; 2) cTnT-ΔE96 requires actin to increase cTnC Ca2+-affinity; and 3) deletion of E96 reduces cTnT stability, likely disrupting crucial thin filament interactions. GENERAL SIGNIFICANCE: The pathological effect of cTnT-ΔE96 is largely manifested by dramatic myofilament Ca2+-sensitization which still persists even after PKA phosphorylation mediated Ca2+-desensitization.

Indexed as

MutationAnimalsCalciumCardiomyopathy, DilatedCyclic AMP-Dependent Protein KinasesGenetic Diseases, InbornHumansMyocardiumMyofibrilsPhosphorylationProtein StabilitySwineTroponin TCalciumCyclic AMP-Dependent Protein KinasesTroponin TCardiac troponin TCircular dichroismFluorescenceRestrictive cardiomyopathySkinned fiberTroponin I phosphorylation

Identifiers

PMID25450489
PMCPMC4276470
OpenAlexW2044600538

What OpenQuestion holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.