Distribution of the Na/K Pumps’ Turnover Rates As a Function of Membrane Potential, Temperature, and Ion Concentration Gradients and Effect of Fluctuations

Huang, Fang; Rabson, David; Chen, Wei

doi:10.1021/jp8054153

Cited by 8 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While potassium and chloride ions are major regulators of resting membrane potential and cell volume, respectively, sodium ions have also a role in maintaining cell membrane potential (Bahlouli et al, 2008;Huang et al, 2009) and in regulating osmotic function (Reusch et al, 1995;Nielsen, 1997;Tokuda et al, 2009). Apart from work on Na þ -channel physiology per se, studies also exist on the involvement of sodium ions in central nervous system development of rats (Beckh et al, 1989), proliferation and differentiation in Xenopus A6 cells (Tanaka et al, 2003), differentiation of chick skeletal muscle in culture (Baumgold et al, 1983a,b) and maturation of the neuromuscular junction in rats (Lupa et al, 1993).…”

Section: Sodiummentioning

confidence: 99%

Ion imaging during axolotl tail regeneration in vivo

Özkucur

Epperlein

Funk

2010

Developmental Dynamics

View full text Add to dashboard Cite

Several studies have reported that endogenous ion currents are involved in a wide range of biological processes from single cell and tissue behavior to regeneration. Various methods are used to assess intracellular and local ion dynamics in biological systems, e.g., patch clamping and vibrating probes. Here, we introduce an approach to detect ion kinetics in vivo using a noninvasive method that can electrophysiologically characterize an entire experimental tissue region or organism. Ion-specific vital dyes have been successfully used for live imaging of intracellular ion dynamics in vitro. Here, we demonstrate that cellular pH, cell membrane potential, calcium, sodium and potassium can be monitored in vivo during tail regeneration in the axolotl (Ambystoma mexicanum) using ion-specific vital dyes. Thus, we suggest that ion-specific vital dyes can be a powerful tool to obtain electrophysiological data during crucial biological events in vivo.

show abstract

Section: Sodiummentioning

confidence: 99%

Ion imaging during axolotl tail regeneration in vivo

Özkucur

Epperlein

Funk

2010

Developmental Dynamics

View full text Add to dashboard Cite

show abstract

“…The ion gradient is formed and maintained by an active ion pump, the Na + , K + ATPase. The sensitivity of many membrane proteins to the membrane potential has provided a means for studying their kinetics by examining the frequency response of transport processes to applied oscillating electric fields or other perturbation (6)(7)(8)(9)(10)(11)(12). The theoretical investigations also show another, perhaps more fundamentally important, nonlinear effect (13).…”

mentioning

confidence: 99%

Stochastically pumped adaptation and directional motion of molecular machines

Astumian

2018

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Recent developments in synthetic molecular motors and pumps have sprung from a remarkable confluence of experiment and theory. Synthetic accomplishments have facilitated the ability to design and create molecules, many of them featuring mechanically bonded components, to carry out specific functions in their environment-walking along a polymeric track, unidirectional circling of one ring about another, synthesizing stereoisomers according to an external protocol, or pumping rings onto a long rod-like molecule to form and maintain high-energy, complex, nonequilibrium structures from simpler antecedents. Progress in the theory of nanoscale stochastic thermodynamics, specifically the generalization and extension of the principle of microscopic reversibility to the single-molecule regime, has enhanced the understanding of the design requirements for achieving strong unidirectional motion and high efficiency of these synthetic molecular machines for harnessing energy from external fluctuations to carry out mechanical and/or chemical functions in their environment. A key insight is that the interaction between the fluctuations and the transition state energies plays a central role in determining the steady-state concentrations. Kinetic asymmetry, a requirement for stochastic adaptation, occurs when there is an imbalance in the effect of the fluctuations on the forward and reverse rate constants. Because of strong viscosity, the motions of the machine can be viewed as mechanical equilibrium processes where mechanical resonances are simply impossible but where the probability distributions for the state occupancies and trajectories are very different from those that would be expected at thermodynamic equilibrium. molecular machine | stochastic pumping | kinetic asymmetry The molecular machines necessary for life must carry out their function in the fluctuating environment of a biological cell. Nowhere is the dynamic aspect of biology at the molecular level more evident than in the bilayer membrane surrounding most cells and organelles, a small portion of which is shown schematically in Fig. 1. Three transmembrane proteins are included in the depiction: (i) an ion channel that provides a conduit for conduction of ions across the membrane; (ii) a molecule that facilitates the transport of some substance, S, across the membrane; and (iii), an NaATPase that uses energy from ATP hydrolysis to maintain ion gradients across the membrane. The transporter acts as a catalyst to reduce the barrier for transport of S. In and of itself, the transporter cannot drive the substance S from low to high chemical potential. The transporter, however, is near a possible source of energy, the ion channel. The ion channel provides a path for conduction of ions from high to low electrochemical potential, thus dissipating energy. Every time the ion channel opens or closes, the local electric field across the membrane changes, and because the flow of ions down the electrochemical gradient when the channel is open dissipates energy, the resulting ...

show abstract

“…2, Table 2). Ionoregulatory processes in ectotherms are temperature dependent, in general with higher turnovers at higher temperatures (Huang et al, 2009;Tattersall et al, 2012). Thus, the increase of copper toxicity at 20 xC relatively to 10 xC may be due to an increased ion turnover at the highest temperature.…”

Section: Discussion Bioassays With Single Substances and Temperature mentioning

confidence: 99%

Comparison of three shredders response to acute stress induced by eucalyptus leaf leachates and copper: single and combined exposure at two distinct temperatures

Gama

Guilhermino

Canhoto

2014

Ann. Limnol. - Int. J. Lim.

View full text Add to dashboard Cite

-The objectives of this study were to compare the sensitivity of three freshwater macroinvertebrate shredder species (Atyaephyra desmarestii, Echinogammarus meridionalis and Schizopelex festiva) to acute stress induced by eucalyptus leaf extracts and copper, independently and in mixtures, and the ability of temperature to influence the chemicals' toxicity. Laboratory bioassays based on mortality with single substances and mixtures were carried out with the three species at 10 and 20 xC. After 96 h of exposure, S. festiva, A. desmarestii and E. meridionalis were found to have differences of sensitivity to copper, eucalyptus leaf extracts and their mixtures, with S. festiva being the least sensitive species at both 10 and 20 xC. The relative sensitivity of A. desmarestii and E. meridionalis to chemical exposure seems to be chemical and temperature dependent. Overall, these findings suggest that chemical stress may modulate the biodiversity of stream shredders communities due to differential sensitivity of individual species to environmental contaminants, and that temperature may influence the process. Thus, more knowledge on the combined effects of multi-stressors is needed, particularly on temperature and chemicals' interactions and on the molecular mechanisms underlying the responses observed at individual level.

show abstract

Distribution of the Na/K Pumps’ Turnover Rates As a Function of Membrane Potential, Temperature, and Ion Concentration Gradients and Effect of Fluctuations

Cited by 8 publications

References 27 publications

Ion imaging during axolotl tail regeneration in vivo

Ion imaging during axolotl tail regeneration in vivo

Stochastically pumped adaptation and directional motion of molecular machines

Comparison of three shredders response to acute stress induced by eucalyptus leaf leachates and copper: single and combined exposure at two distinct temperatures

Contact Info

Product

Resources

About