Abstract：
:Understanding the process of Ca(2+)/Mg(2+)exchange during muscle excitation and relaxation is fundamental to elucidating the mechanism of Ca(2+)-regulated muscle contraction. During the resting phase, the C-domain of cardiac troponin C may be occupied by either Ca(2+)or Mg(2+). Here, complexes of recombinant cardiac troponin C(81-161) and the N terminus of cardiac troponin I, representing residues 33-80, were generated in the presence of saturating Mg(2+). Heteronuclear multi-dimensional nuclear magnetic resonance experiments were used to obtain backbone assignments of the Mg(2+)-loaded complex. In the presence of cardiac troponin I, the affinity of site IV for Mg(2+)is increased. Comparison of Mg(2+)and Ca(2+)-loaded complexes reveals that chemical shift differences are primarily localized to metal-binding sites III and IV, defining positions within these sites that have distinct Ca(2+)/Mg(2+)conformations. The observed transition from the Mg(2+)-loaded to Ca(2+)-loaded form demonstrates that sites III and IV fill simultaneously with Ca(2+)displacing Mg(2+). However, even in the absence of excess Ca(2+), Mg(2+)does not readily displace Ca(2+)in the isolated binary complex. Thus, the Mg(2+)-loaded conformer may only represent a small fraction of the total cardiac troponin C found in the sarcomere.
journal_name
J Mol Cell Cardioljournal_title
Journal of molecular and cellular cardiologyauthors
Finley N,Dvoretsky A,Rosevear PRdoi
10.1006/jmcc.2000.1174keywords:
subject
Has Abstractpub_date
2000-08-01 00:00:00pages
1439-46issue
8eissn
0022-2828issn
1095-8584pii
S0022-2828(00)91174-Xjournal_volume
32pub_type
杂志文章abstract：:The effects of rate changes and 'premature' stimulation on the slow inward current of cardiac muscle were studied in the frog atrium. The effects of adrenaline under these conditions was investigated. It was found that adrenaline markedly accelerates the repriming kinetics of the slow inward channel. Adrenaline at low...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/s0022-2828(84)80618-5
更新日期：1984-05-01 00:00:00
abstract：:Pacemaker (HCN) channels have a key role in the generation and modulation of spontaneous activity of sinoatrial node myocytes. Previous work has shown that compartmentation of HCN4 pacemaker channels within caveolae regulates important functions, but the molecular mechanism responsible is still unknown. HCN channels h...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2012.05.013
更新日期：2012-08-01 00:00:00
abstract：:Beta-adrenoceptor is over-stimulated during myocardial ischemia, in which hydrogen sulphide (H2S) concentration was found to be lowered. The present study attempted to investigate if H2S modulates beta-adrenoceptor function and the underlying mechanism. We examined the effect of NaHS (a H2S donor) on myocyte contracti...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2008.01.007
更新日期：2008-04-01 00:00:00
abstract：BACKGROUND:Cultured adult mouse and rat cardiomyocytes are the best and low-cost cell model for cardiac cellular physiology, pathology, drug toxicity screening, and intervention. The functions of mouse cardiomyocytes decline faster than rat cardiomyocytes in culture conditions. However, little is known about the differ...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2019.09.006
更新日期：2019-11-01 00:00:00
abstract：:α-Keto acids (α-KAs) are not just metabolic intermediates but are also powerful modulators of different cellular pathways. Here, we tested the hypothesis that α-KA concentrations are regulated by complex II (succinate dehydrogenase=SDH), which represents an intersection between the mitochondrial respiratory chain for ...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2010.09.023
更新日期：2010-12-01 00:00:00
abstract：:The adult newt cardiac ventricular myocyte has been successfully placed in cell culture and has been shown to undergo in vitro DNA synthesis. Although several growth factors have been reported to increase DNA synthesis in cardiac myocytes in vitro, PDGF has not been reported to do so, but has been shown to be active i...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/0022-2828(92)91870-b
更新日期：1992-09-01 00:00:00
abstract：:The rapid application of caffeine to cardiac myocytes is commonly used to assess changes in the Ca2+ content of the sarcoplasmic reticulum (SR) and to study other parameters of intracellular Ca2+ regulation. Here we examined the effects of rapid caffeine application on membrane potential, intracellular Ca2+, and cell ...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1998.0782
更新日期：1998-11-01 00:00:00
abstract：:Cardiac troponin I (cTnI), the inhibitory-unit, and cardiac troponin T (cTnT), the tropomyosin-binding unit together with the Ca-binding unit (cTnC) of the hetero-trimeric troponin complex signal activation of the sarcomeres of the adult cardiac myocyte. The unique structure and heart myocyte restricted expression of ...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章,评审
doi：10.1016/j.yjmcc.2020.05.010
更新日期：2020-06-01 00:00:00
abstract：:Cardiac myocytes in rat hearts lose their ability to undergo cytokinesis between day 3 and day 4, resulting in the formation of binucleated myocytes. Failure in the formation of the actin-myosin contractile ring could cause cardiac myocytes to be defective in cytokinesis. Enzymatically isolated cardiac myocytes from 2...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1997.0381
更新日期：1997-06-01 00:00:00
abstract：:The mechanism of the antiadrenergic action of adenosine in the heart was investigated by examining the effects of phenylisopropyladenosine (PIA), an adenosine A1 receptor agonist, on beta-adrenergic receptor and non-receptor elicited increases in adenylyl cyclase activity of guinea-pig ventricular membranes. These mem...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/0022-2828(90)90981-7
更新日期：1990-12-01 00:00:00
abstract：BACKGROUND:Duchenne muscular dystrophy (DMD) is an X-linked disease characterized by skeletal muscle degeneration and a significant cardiomyopathy secondary to cardiomyocyte damage and myocardial loss. The molecular basis of DMD lies in the absence of the protein dystrophin, which plays critical roles in mechanical mem...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2019.01.013
更新日期：2019-03-01 00:00:00
abstract：:Our previous studies showed that homocysteine (Hcy) reduces endothelial progenitor cell (EPC) numbers and impairs functional activity. However, the mechanisms by which Hcy reduces EPCs numbers and activity remain to be determined. Recent studies have demonstrated that reduced EPCs numbers and activity was associated w...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2006.01.011
更新日期：2006-05-01 00:00:00
abstract：:Since systemic actions of thyroid hormone increase cardiac work, direct effects of T3 on myocardial protein turnover may be obscured in the intact animal. For this reason, the effects of T3 on synthesis and degradation of cellular protein were measured in replicate cultures of cardiac myocytes obtained from chick embr...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/s0022-2828(85)80103-6
更新日期：1985-09-01 00:00:00
abstract：:To elucidate the role of bicarbonate-dependent mechanisms and Na+/H+ exchange in maintenance of physiological intracellular pH (pHi) under various steady-state conditions, phosphorus NMR spectra were taken in isovolumically-contracting, perfused ferret hearts. Switching the perfusate from HCO3-/CO2 to HEPES buffer sig...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1994.1099
更新日期：1994-07-01 00:00:00
abstract：:Phospholamban (PLN) is a key regulator of cardiac contraction and relaxation through its inhibition of the sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA2a). The inhibitory effect is attenuated upon protein kinase A (PKA) dependent phosphorylation of PLN. PLN exists in an equilibrium of pentamers and monomers. While...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2014.12.020
更新日期：2015-03-01 00:00:00
abstract：:Cardiac adaptation to aerobic exercise training includes improved cardiomyocyte contractility and calcium handling. Our objective was to determine whether cytosolic calcium/calmodulin-dependent kinase II and its downstream targets are modulated by exercise training. A six-week aerobic interval training program by trea...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2007.06.013
更新日期：2007-09-01 00:00:00
abstract：:Fibroblast growth factor-2 (FGF-2), administered to the isolated rat heart by perfusion and under constant pressure, is protective against ischemia-reperfusion (I-R). Here we have investigated whether FGF-2 cardioprotection: (a) is dependent on flow modulation; (b) is linked to effects on contractility; (c) is mediate...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1998.0832
更新日期：1998-12-01 00:00:00
abstract：:The regulation of vascular smooth muscle cell (VSMC) proliferation is an important issue because it has major implications for the prevention of pathological vascular conditions. Using microRNA array screen, we found the expression levels of 200 unique miRNAs in hyperplasic tissues. Among them, miR-200c expression sub...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2015.03.011
更新日期：2015-05-01 00:00:00
abstract：:We report a novel action of intracellular adenosine monophosphate (AMP) to inhibit beta-adrenergic signaling in isolated rat ventricular myocytes. Extracellular application of adenosine or AMP suppressed isoproterenol (Iso)-induced prolongation of action potential duration (APD). This effect was completely abolished b...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2007.07.059
更新日期：2007-11-01 00:00:00
abstract：:The question was investigated whether mild acidosis can provide energetic protection on the hypoxic myocardial cell by mechanisms other than negative inotropy. The experimental model used was quiescent ventricular cardiomyocytes isolated from the adult rat. The extracellular pH (pHe) in modified hypoxic Tyrode's solut...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/0022-2828(92)91159-3
更新日期：1992-01-01 00:00:00
abstract：:A dose-response study concerning the importance of the flow rate (0.5 to 12 ml/min) and volume (2.5 to 60 ml) of calcium-free coronary perfusion (duration 5 min) in the induction of a calcium paradox on reperfusion (duration 15 min) with calcium-containing medium has been performed in the isolated rat heart (37 degree...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/s0022-2828(85)80076-6
更新日期：1985-10-01 00:00:00
abstract：:Oxygen deprivation for prolonged periods leads to cardiac cell death and ventricular dysfunction. The ability to prevent myocardial cell death would be of significant therapeutic value in maintaining cardiac function after injury. While caspases have been suggested to play a critical role in apoptosis, their involveme...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1999.1057
更新日期：2000-01-01 00:00:00
abstract：:Aspirin and clopidogrel are used therapeutically for their anti-platelet effects. We examined the effects of aspirin and clopidogrel on basal and beta-adrenoceptor (beta-AR)-mediated platelet nitric oxide (NO) synthesis in healthy subjects and patients with coronary heart disease (CHD). Healthy subjects (n=19) were ra...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章,随机对照试验
doi：10.1016/j.yjmcc.2008.05.015
更新日期：2008-08-01 00:00:00
abstract：:A cardiac muscle sarcolemmal preparation, enriched in adenylate cyclase, Na+, K+ -ATPase, beta, muscarinic and ouabain receptors, also contained endogenous protein kinase activity. Phosphorylation of sarcolemmal membrane proteins by the endogenous protein kinase occurred mainly on 22 000 and 12 000 Mr proteins. To det...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/s0022-2828(85)80124-3
更新日期：1985-11-01 00:00:00
abstract：:The two-pore domain potassium (K(+)) channel TWIK-1 (or K2P1.1) contributes to background K(+) conductance in diverse cell types. TWIK-1, encoded by the KCNK1 gene, is present in the human heart with robust expression in the atria, however its physiological significance is unknown. To evaluate the cardiac effects of T...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2016.04.006
更新日期：2016-08-01 00:00:00
abstract：:The loss of cardiomyocytes by apoptosis and the subsequent replacement by fibrous connective tissues are important features of cardiac remodeling in adult heart disease. In children with CHD, however, the cellular and molecular mechanisms of heart failure have not yet been fully understood because of the anatomical an...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2007.05.011
更新日期：2007-09-01 00:00:00
abstract：:The aim was to determine whether adaptation to chronic hypoxia protects the heart against ischemic arrhythmias and whether ATP-dependent potassium channels (K(ATP)) play a role in the antiarrhythmic mechanism. Adult male rats were adapted to intermittent high altitude hypoxia (5000 m, 4 h/day) and susceptibility to is...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1999.1013
更新日期：1999-10-01 00:00:00
abstract：:In the present investigation, the effects of forskolin on intracellular sodium activity were studied in quiescent and electrically stimulated cardiac Purkinje fibers from sheep using Na+-sensitive microelectrodes. Also assessed, were the effects of this promoter of cytosolic cAMP production on resting membrane potenti...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/s0022-2828(87)80617-x
更新日期：1987-09-01 00:00:00
abstract：:To demonstrate a direct protective effect of propofol on myocardial contractile performance during an ischemic episode and investigate underlying mechanisms, isolated adult rat ventricular cardiomyocytes were subjected for 2 h to (i) ischemic medium containing 2-deoxyglucose (20 mM), gassed with 100% N(2) at pH 6.4, (...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2006.12.002
更新日期：2007-03-01 00:00:00
abstract：:A reduced adaptation rate of the myocardium must, in many cases, be made responsible for heart insufficiency of old patients. The present investigations are aimed towards the question whether heart in old age is accompanied by a loss of myocardial cells and whether a polyploidisation of heart muscle cells takes place ...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/s0022-2828(86)80981-6
更新日期：1986-01-01 00:00:00
