scholarly journals Observing a Model Ion Channel Gating Action in Model Cell Membranes in Real Time in Situ: Membrane Potential Change Induced Alamethicin Orientation Change

2012 ◽  
Vol 134 (14) ◽  
pp. 6237-6243 ◽  
Author(s):  
Shuji Ye ◽  
Hongchun Li ◽  
Feng Wei ◽  
Joshua Jasensky ◽  
Andrew P. Boughton ◽  
...  
2020 ◽  
Vol 20 (5) ◽  
Author(s):  
Walrati Limapichat ◽  
Wichai Pornthanakasem ◽  
Chatchaya Satitthammachart ◽  
Penchit Chitnumsub ◽  
Ubolsree Leartsakulpanich

ABSTRACT In yeast, adaptation to varying conditions often requires proper regulation of the plasma membrane potential. To determine yeast membrane potential change, optical methods involving potentiometric dyes have been supplemental to the direct electrode-based method. However, the hydrophobic nature of the dyes and their slow distribution across the membrane still limits their utilization. Genetically encoded voltage indicator (GEVI) proteins employed in neuroscience offer a tantalizing alternative for monitoring yeast membrane potential change. In this work, several widely used GEVI proteins were assessed in Saccharomyces cerevisiae for their expression and function as a voltage reporter. Among them, only ArcLight and Accelerated Sensor of Action Potential (ASAP) proteins could be expressed and transported to the plasma membrane. While the voltage-sensing capability was demonstrated for both ArcLight and ASAP, ArcLight fluorescence was sensitive to the intracellular pH change concurrently with the voltage change. Therefore, we established that ASAP is the more suitable GEVI protein for reporting yeast membrane potential change. This voltage-sensing reporter for yeast based on ASAP offers a new effective strategy for real-time optical detection of yeast membrane potential change, which potentially facilitates many areas of yeast research including optimizing growth conditions for industrial use and investigating yeast ion transport system.


2007 ◽  
Vol 23 (6) ◽  
pp. 348-356 ◽  
Author(s):  
Vincent Cazenave-Loustalet ◽  
Qing-Li Qiao ◽  
Li-Ming Li ◽  
Qiu-Shi Ren

1986 ◽  
Vol 56 (3) ◽  
pp. 702-717 ◽  
Author(s):  
M. Takahata ◽  
M. Hisada

The occurrence of the uropod steering response as one of the equilibrium reflexes to body rolling in crayfish is significantly facilitated if the stimulus is given while the animal is performing the abdominal posture movement. This facilitation of the descending statocyst pathway by the abdominal posture system takes place between the uropod motor neurons and the statocyst interneurons, which directly project from the brain to the terminal abdominal ganglion where the motor neurons originate. To elucidate the synaptic mechanisms underlying the postural facilitation of the steering response, we analyzed in this study the activity of an identified set of uropod motor neurons during the fictive abdominal extension movement in the whole-animal preparation. Intracellular recordings from the dendritic branches of uropod motor neurons revealed that they were continuously excited during the fictive abdominal extension. The large fast motor neurons usually showed a sustained depolarization of the subthreshold magnitude. The small slow ones showed a suprathreshold sustained depolarization with spikes superimposed. Putative inhibitory motor neurons, on the other hand, showed a sustained hyperpolarization with their spontaneous spike discharge suppressed. The discrete synaptic potentials could hardly be distinguished and, instead, small fluctuations of the membrane potential were observed during the sustained depolarization of both the fast and slow motor neurons. Occasionally, large discrete synaptic potentials could be observed to be superimposed on the sustained depolarization. The occurring frequency of these synaptic potentials showed, however, no significant increase associated with the sustained depolarization. It hence seemed unlikely that these potentials were responsible for producing the sustained depolarization. Their amplitude during the sustained depolarization was smaller than that observed during the quiescent state. The sustained membrane potential change during the fictive abdominal movement was also observed in many neurons other than motor neurons, including local nonspiking interneurons and mechanosensory spiking interneurons. Both motor neurons and interneurons showed a decrease in their membrane resistance during the sustained membrane potential change. We concluded that the sustained depolarization of uropod motor neurons during the fictive abdominal extension was produced by the summation of small chemically transmitted postsynaptic potentials.(ABSTRACT TRUNCATED AT 400 WORDS)


1994 ◽  
Vol 4 (2) ◽  
pp. 101-113 ◽  
Author(s):  
Kazunori Odashima ◽  
Ryuichi Naganawa ◽  
Hanna Radecka ◽  
Masamitsu Kataoka ◽  
Eiichi Kimura ◽  
...  

2007 ◽  
Vol 35 (5) ◽  
pp. 1080-1082 ◽  
Author(s):  
T.W. Claydon ◽  
D. Fedida

VCF (voltage clamp fluorimetry) provides a powerful technique to observe real-time conformational changes that are associated with ion channel gating. The present review highlights the insights such experiments have provided in understanding Kv (voltage-gated potassium) channel gating, with particular emphasis on the study of mammalian Kv1 channels. Further applications of VCF that would contribute to our understanding of the modulation of Kv channels in health and disease are also discussed.


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