What does this research mean for the field?

The ΔLys-210 troponin T mutation, which causes dilated cardiomyopathy, reduces maximum ATPase activation and sliding speed while altering Ca2+ sensitivity, producing functional consequences that are distinct from hypertrophic cardiomyopathy-causing mutations like R92Q. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To compare the in vitro regulatory consequences of the dilated cardiomyopathy mutation ΔLys-210 and the hypertrophic cardiomyopathy mutation R92Q in human cardiac troponin T.

October 1, 2002Journal of Biological ChemistryOpen Access

Alterations in Thin Filament Regulation Induced by a Human Cardiac Troponin T Mutant That Causes Dilated Cardiomyopathy Are Distinct from Those Induced by Troponin T Mutants That Cause Hypertrophic Cardiomyopathy

Q: What is the clinical evidence from this study?

Population: Dilated cardiomyopathy and Hypertrophic cardiomyopathy. Intervention: Recombinant human cardiac troponin with ΔLys-210 or R92Q troponin T mutants vs. Wild type troponin T. Primary outcome: In vitro regulatory properties (ATPase activity and sliding speed).

View Full Paper

Ask AI

Bookmark

Key result

The ΔLys-210 troponin T mutant reduced maximum ATPase activation and sliding speed and increased Ca2+ sensitivity (ΔpCa50 = +0.2), effects distinct from the R92Q hypertrophic cardiomyopathy mutant.

Population

In vitro reconstituted thin filaments using recombinant human cardiac troponin, rabbit skeletal muscle…

Comparison

Recombinant human cardiac troponin containing… vs Recombinant human cardiac troponin containing…

Design

Preclinical

Authors

PRPaul RobinsonUniversity College London Hospitals NHS Foundation Trust MMM MirzaRussian Academy of Sciences AKAdam KnottRoche (United Kingdom)

Discussion

Member takes

Implication

Distinguishes DCM-linked troponin effects from HCM in vitro; hypothesis-generating for distinct cardiomyopathy triggers pending human validation.

Key Points

To compare the in vitro regulatory consequences of the dilated cardiomyopathy mutation ΔLys-210 and the hypertrophic cardiomyopathy mutation R92Q in human cardiac troponin T.
Reconstituted recombinant human cardiac troponin complexes containing wild-type, ΔLys-210, or R92Q troponin T alongside actin and tropomyosin.
Assayed actin-tropomyosin-activated myosin subfragment-1 ATPase activity and thin filament sliding velocity across calcium concentrations from pCa 8.5 to 4.5.
Troponin containing ΔLys-210 retained wild-type inhibition at pCa 8.5 (>80%) but substantially reduced maximal ATPase activation at pCa 4.5, increased Ca2+ sensitivity (ΔpCa50 = +0.2 pCa units), abolished cooperativity, and reduced filament sliding speed.
Equimolar mixtures of wild-type and ΔLys-210 troponin T decreased Ca2+ sensitivity relative to wild-type while preserving the diminished maximal ATPase activation and sliding velocity.
In contrast, the R92Q troponin T mutant conferred reduced inhibition at pCa 8.5, heightened maximal activation at pCa 4.5, and increased Ca2+ sensitivity with unaltered cooperativity.

Structured PICO

Population

In vitro reconstituted thin filaments using recombinant human cardiac troponin, rabbit skeletal muscle actin, rabbit and human cardiac muscle α-tropomyosin, and subfragment-1 (S-1) from rabbit skeletal muscle myosin

Intervention

Recombinant human cardiac troponin containing the ΔLys-210 troponin T mutant (causes dilated cardiomyopathy)

Comparator

Recombinant human cardiac troponin containing wild type troponin T or the R92Q troponin T mutant (causes hypertrophic cardiomyopathy)

Outcome

Actin-tropomyosin-activated myosin subfragment-1 ATPase activity and sliding speed in in vitro motility assaysurrogate

The ΔLys-210 troponin T mutation causing DCM produces distinct functional alterations (reduced ATPase activation and sliding speed, loss of cooperativity) compared to HCM mutations, suggesting different primary triggers for these cardiomyopathies.

Cite This Study

Robinson et al. (2002) studied Dilated cardiomyopathy and Hypertrophic cardiomyopathy. Recombinant human cardiac troponin with ΔLys-210 or R92Q troponin T mutants vs. Wild type troponin T was evaluated on In vitro regulatory properties (ATPase activity and sliding speed). The ΔLys-210 troponin T mutant reduced maximum ATPase activation and sliding speed and increased Ca2+ sensitivity (ΔpCa50 = +0.2), effects distinct from the R92Q hypertrophic cardiomyopathy mutant.

synapsesocial.com/papers/6a1540bed64fa333899f6e75 https://doi.org/10.1074/jbc.m203446200

View Full Paper

Ask AI

Bookmark

Implication

Distinguishes DCM-linked troponin effects from HCM in vitro; hypothesis-generating for distinct cardiomyopathy triggers pending human validation.

Alterations in Thin Filament Regulation Induced by a Human Cardiac Troponin T Mutant That Causes Dilated Cardiomyopathy Are Distinct from Those Induced by Troponin T Mutants That Cause Hypertrophic Cardiomyopathy

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Alterations in Thin Filament Regulation Induced by a Human Cardiac Troponin T Mutant That Causes Dilated Cardiomyopathy Are Distinct from Those Induced by Troponin T Mutants That Cause Hypertrophic Cardiomyopathy

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider