Calcium current activated upon hyperpolarization of Paramecium tetraurelia.
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منابع مشابه
Calcium current activated upon hyperpolarization of Paramecium tetraurelia
Hyperpolarization of Paramecium tetraurelia under conditions where K+ currents are suppressed elicits an inward current that activates rapidly toward a peak at 25-80 ms and decays thereafter. This peak current (Ihyp) is not affected by removing Cl ions from the microelectrodes used to clamp membrane potential, or by changing extracellular Cl- concentration, but is lost upon removing extracellul...
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The Ca2+ current activated upon hyperpolarization of Paramecium tetraurelia decays over a period of 150-200 ms during sustained steps under voltage clamp. At membrane potentials between -70 and approximately -100 mV, the time course of this inactivation is described by a single exponential function. Steps negative to approximately -100 mV elicit currents that decay biexponentially, however. Thr...
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Early in eukaryotic evolution, the cell has evolved a considerable inventory of proteins engaged in the regulation of intracellular Ca(2+) concentrations, not only to avoid toxic effects but beyond that to exploit the signaling capacity of Ca(2+) by small changes in local concentration. Among protozoa, the ciliate Paramecium may now be one of the best analyzed models. Ciliary activity and exo-/...
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Late K-outward currents upon membrane depolarization were recorded in Paramecium tetraurelia under a voltage clamp. A Ca-induced K-outward component is demonstrated by subtracting the value of the outward current in a pawn A mutant lacking functional Ca-channels (pwA500). The Ca-induced K-outward current activates slowly, reaching a peak after 100 to 1000 ms. The current then remains steady or ...
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The macronuclear ribosomal DNA (rDNA) of the ciliated protozoan Paramecium tetraurelia (stock 51) was analyzed by digestion with restriction endonucleases. The fragments which contained ribosomal RNA (rRNA) coding sequences and spacer sequences were identified. The spacer sequences exhibited some heterogeneity in size. The genes coding for 5.8S RNA, but not for 5S RNA, are linked to the 17S and...
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ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 1992
ISSN: 0022-1295,1540-7748
DOI: 10.1085/jgp.100.2.233