Tetrodotoxin-sensitive voltage-dependent Na currents recorded from Xenopus oocytes injected with mammalian cardiac muscle RNA

Sutton, Fedora; Davidson, Norman; Lester, Henry A.

doi:10.1016/0169-328x(88)90065-4

Cited by 18 publications

(12 citation statements)

References 16 publications

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“…Recently, Sutton et al [5] reported that injection of poly(A) ÷ mRNA prepared from rabbit and rat cardiac muscle resulted in functional expression of a small 1Na in Xenopus oocytes. Contrary to what might be expected for cardiac Na + channels, this INa Abbreviations: TTX, tetrodotoxin; STX, saxito×in; INa, sodium current; TTX-S, TTX-sensitive; TTX-R, TTX-resistant; RH-I, rat heart I Na + cllannel to TTX (TTX-S).…”

Section: Introductionmentioning

confidence: 99%

Functional expression of the rat heart I Na⁺ channel isoform Demonstration of properties characteristic of native cardiac Na⁺ channels

Cribbs¹,

Satin²,

Fozzard³

et al. 1990

FEBS Letters

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We describe the expression of functional Na+ channel in Xenopus oocytes injected with cRNA transcribed from the rat heart 1 cDNA clone. The expressed rat heart 1 Na+ currents show kinetic properties and resistance to tetrodotoxin and saxitoxin which are characteristic of native cardiac Na+ currents. The primary amino acid sequence of the rat heart 1 α‐subunit is therefore sufficient for expression of of tetrodotoxin resistance, and the rat heart 1 clone is likely to account for the tetrodotoxin‐resistant phenotype of cardiac and denervated skeletal muscle.

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Section: Introductionmentioning

confidence: 99%

Functional expression of the rat heart I Na⁺ channel isoform Demonstration of properties characteristic of native cardiac Na⁺ channels

Cribbs¹,

Satin²,

Fozzard³

et al. 1990

FEBS Letters

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“…Ion channel expression in oocytes was monitored by the TEVC technique as described (Dascal and Cohen, 1987;Sutton et al, 1988) using an Axoclamp 2A amplifier (Axon Instruments). Voltage and current microelectrodes were filled with 3 m KCl; electrodes measuring 0.5-to 2-M⍀ resistance in 96 mm Na ϩ solution were used.…”

Section: Tevc Measurementsmentioning

confidence: 99%

Distinct Abscisic Acid Signaling Pathways for Modulation of Guard Cell versus Mesophyll Cell Potassium Channels Revealed by Expression Studies in Xenopus laevisOocytes

et al. 2000

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Regulation of guard cell ion transport by abscisic acid (ABA) and in particular ABA inhibition of a guard cell inward K ϩ current (I Kin ) is well documented. However, little is known concerning ABA effects on ion transport in other plant cell types. Here we applied patch clamp techniques to mesophyll cell protoplasts of fava bean (Vicia faba cv Long Pod) plants and demonstrated ABA inhibition of an outward K ϩ current (I Kout ). When mesophyll cell protoplast mRNA (mesophyll mRNA) was expressed in Xenopus laevis oocytes, I Kout was generated that displayed similar properties to I Kout observed from direct analysis of mesophyll cell protoplasts. I Kout expressed by mesophyll mRNA-injected oocytes was inhibited by ABA, indicating that the ABA signal transduction pathway observed in mesophyll cells was preserved in the frog oocytes. Co-injection of oocytes with guard cell protoplast mRNA and cRNA for KAT1, an inward K ϩ channel expressed in guard cells, resulted in I Kin that was similarly inhibited by ABA. However, oocytes co-injected with mesophyll mRNA and KAT1 cRNA produced I Kin that was not inhibited by ABA. These results demonstrate that the mesophyll-encoded signaling mechanism could not substitute for the guard cell pathway. These findings indicate that mesophyll cells and guard cells use distinct and different receptor types and/or signal transduction pathways in ABA regulation of K ϩ channels.

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“…However, previous attempts to functionally express cardiac TTX-I NaChs in oocytes using RNA from mammalian heart have met with variable success (11)(12)(13). While functional expression of the rat muscle TTX-I isoform (rSkM2) from its cloned cDNA has been accomplished (14), the applicability of these findings to the homologous human cardiac NaCh is unknown.…”

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confidence: 99%

Primary structure and functional expression of the human cardiac tetrodotoxin-insensitive voltage-dependent sodium channel.

Gellens

George

Chen

et al. 1992

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

579

375

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The principal voltage-sensitive sodium channel from human heart has been cloned, sequenced, and functionally expressed. The cDNA, designated hH1, encodes a 2016-amino acid protein that is homologous to other members of the sodium channel multigene family and bears >90% identity to the tetrodotoxin-insensitive sodium channel characteristic of rat heart and of immature and denervated rat skeletal muscle. Northern blot analysis demonstrates an =9.0-kilobase transcript expressed in human atrial and ventricular cardiac muscle but not in adult skeletal muscle, brain, myometrium, liver, or spleen. When expressed in Xenopus oocytes, hHl exhibits rapid activation and inactivation kinetics similar to native cardiac sodium channels. The single channel conductance of hHl to sodium ions is about twice that of the homologous rat channel and hHl is more resistant to block by tetrodotoxin (ICso = 5.7 pM). hHl is also resistant to Iu-conotoxin but sensitive to block by therapeutic concentrations of lidocaine in a use-dependent manner.

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Tetrodotoxin-sensitive voltage-dependent Na currents recorded from Xenopus oocytes injected with mammalian cardiac muscle RNA

Cited by 18 publications

References 16 publications

Functional expression of the rat heart I Na⁺ channel isoform Demonstration of properties characteristic of native cardiac Na⁺ channels

Functional expression of the rat heart I Na⁺ channel isoform Demonstration of properties characteristic of native cardiac Na⁺ channels

Distinct Abscisic Acid Signaling Pathways for Modulation of Guard Cell versus Mesophyll Cell Potassium Channels Revealed by Expression Studies in Xenopus laevisOocytes

Primary structure and functional expression of the human cardiac tetrodotoxin-insensitive voltage-dependent sodium channel.

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Tetrodotoxin-sensitive voltage-dependent Na currents recorded from Xenopus oocytes injected with mammalian cardiac muscle RNA

Cited by 18 publications

References 16 publications

Functional expression of the rat heart I Na+ channel isoform Demonstration of properties characteristic of native cardiac Na+ channels

Functional expression of the rat heart I Na+ channel isoform Demonstration of properties characteristic of native cardiac Na+ channels

Distinct Abscisic Acid Signaling Pathways for Modulation of Guard Cell versus Mesophyll Cell Potassium Channels Revealed by Expression Studies in Xenopus laevisOocytes

Primary structure and functional expression of the human cardiac tetrodotoxin-insensitive voltage-dependent sodium channel.

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Functional expression of the rat heart I Na⁺ channel isoform Demonstration of properties characteristic of native cardiac Na⁺ channels

Functional expression of the rat heart I Na⁺ channel isoform Demonstration of properties characteristic of native cardiac Na⁺ channels