ArticleBiophysical journal2002
Troponin-tropomyosin: an allosteric switch or a steric blocker?
Article in Biophysical journal, 2002. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers.
What it found
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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.
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Who cites it
13 citing papers in PubMed, 37 citations in OpenAlex.
- The Twisting and Untwisting of Actin and Tropomyosin Filaments Are Involved in the Molecular Mechanisms of Muscle Contraction, and Their Disruption Can Result in Muscle Disorders.International journal of molecular sciences · 2025Review
- The Primary Causes of Muscle Dysfunction Associated with the Point Mutations in Tpm3.12; Conformational Analysis of Mutant Proteins as a Tool for Classification of Myopathies.International journal of molecular sciences · 2018Article
- Stepwise C-Terminal Truncation of Cardiac Troponin T Alters Function at Low and Saturating CaBiophysical journal · 2018Article
- Molecular mechanisms of dysfunction of muscle fibres associated with Glu139 deletion in TPM2 gene.Scientific reports · 2017Article
- Troponin C Mutations Partially Stabilize the Active State of Regulated Actin and Fully Stabilize the Active State When Paired with Δ14 TnT.Biochemistry · 2017Article
- Disease causing mutations of troponin alter regulated actin state distributions.Journal of muscle research and cell motility · 2012Review
- The C-terminus of troponin T is essential for maintaining the inactive state of regulated actin.Biophysical journal · 2012Article
- Acrylodan-labeled smooth muscle tropomyosin reports differences in the effects of troponin and caldesmon in the transition from the active state to the inactive state.Biochemistry · 2011Article
- Kinetics of regulated actin transitions measured by probes on tropomyosin.Biophysical journal · 2010Article
- Insights into the kinetics of Ca2+-regulated contraction and relaxation from myofibril studies.Pflugers Archiv : European journal of physiology · 2009Article
- Role of actin C-terminus in regulation of striated muscle thin filament.Biophysical journal · 2008Article
- Ca2+ and ionic strength dependencies of S1-ADP binding to actin-tropomyosin-troponin: regulatory implications.Biophysical journal · 2004Article
- What is the role of tropomyosin in the regulation of muscle contraction?Journal of muscle research and cell motility · 2003Review
Corrections and comments
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Authors and funding
3 authors at 1 institution in 1 country.
Funding
Abstract
The interaction of myosin subfragment 1 (S1) with actin-tropomyosin-troponin (regulated actin) is highly nucleotide dependent. The binding of S1 or S1-ADP (but not S1-ATP nor N,N'-rho-phenylenedimaleimide-modified S1-ATP) to regulated actin activates ATP hydrolysis even in the absence of Ca(2+). Investigations with S1 and S1-ADP have led to the idea that some actin sites are directly blocked toward the binding of S1 either by tropomyosin or troponin. The blocked state is thought to occur only at ionic strengths greater than 50 mM. The question is whether nonactivating S1 binding is blocked under the same conditions. We show that troponin inhibits binding of the nonactivating state, N,N'-rho-phenylenedimaleimide-S1-ATP, to actin but only when tropomyosin is absent. A lag in the rate of binding of activating S1 to actin (an indicator of the blocked state) occurs only in the presence of tropomyosin. Thus, tropomyosin inhibits binding of rigor S1 but not S1-ATP-like states. No evidence for an ionic strength-dependent change in the mechanism of regulation was observed either from measurements of the rate of activating S1 binding or from the equilibrium binding of nonactivating S1 to actin. At all conditions examined, N,N'-rho-phenylenedimaleimide-S1-ATP bound to regulated actin in the absence of Ca(2+). These results support the view of regulation in which tropomyosin movement is an allosteric switch that is modulated by activating myosin binding but that does not function solely by regulating myosin binding.
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Registered trials
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.