Contribution of the NH2 terminus of Kv2.1 to channel activation

Juan M. Pascual, Char Chang Shieh, Glenn E. Kirsch, Arthur M. Brown

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Opening and closing of voltage-operated channels requires the interaction of diverse structural elements. One approach to the identification of channel domains that participate in gating is to locate the sites of action of modifiers. Covalent reaction of Kv2.1 channels with the neutral, sulfhydryl-specific methylmethanethiosulfonate (MMTS) caused a slowing of channel gating with a predominant effect on the kinetics of activation. These effects were also obtained after intracellular, but not extracellular, application of a charged MMTS analog. Single channel analysis revealed that MMTS acted primarily by prolonging the latency to first opening without substantially affecting gating transitions after the channel first opens and until it inactivates. To localize the channel cysteine(s) with which MMTS reacts, we generated NH2- and COOH-terminal deletion mutants and a construct in which all three cysteines in transmembrane regions were substituted. Only the NH2-terminal deletion construct gave rise to currents that activated slowly and displayed MMTS-insensitive kinetics. These results show that the NH2-terminal tail of Kv2.1 participates in transitions leading to activation through interactions involving reduced cysteine(s) that can be modulated from the cytoplasmic phase.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Cell Physiology
Volume273
Issue number6 42-6
StatePublished - 1997

Fingerprint

Cysteine
Chemical activation
Kinetics
Electric potential

Keywords

  • Chemical modification
  • Cysteine
  • Electrophysiology
  • Site-directed mutagenesis

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Cell Biology
  • Physiology
  • Physiology (medical)

Cite this

Contribution of the NH2 terminus of Kv2.1 to channel activation. / Pascual, Juan M.; Shieh, Char Chang; Kirsch, Glenn E.; Brown, Arthur M.

In: American Journal of Physiology - Cell Physiology, Vol. 273, No. 6 42-6, 1997.

Research output: Contribution to journalArticle

Pascual, Juan M. ; Shieh, Char Chang ; Kirsch, Glenn E. ; Brown, Arthur M. / Contribution of the NH2 terminus of Kv2.1 to channel activation. In: American Journal of Physiology - Cell Physiology. 1997 ; Vol. 273, No. 6 42-6.
@article{ad929269297542fa9ee04e60bc0bb4b6,
title = "Contribution of the NH2 terminus of Kv2.1 to channel activation",
abstract = "Opening and closing of voltage-operated channels requires the interaction of diverse structural elements. One approach to the identification of channel domains that participate in gating is to locate the sites of action of modifiers. Covalent reaction of Kv2.1 channels with the neutral, sulfhydryl-specific methylmethanethiosulfonate (MMTS) caused a slowing of channel gating with a predominant effect on the kinetics of activation. These effects were also obtained after intracellular, but not extracellular, application of a charged MMTS analog. Single channel analysis revealed that MMTS acted primarily by prolonging the latency to first opening without substantially affecting gating transitions after the channel first opens and until it inactivates. To localize the channel cysteine(s) with which MMTS reacts, we generated NH2- and COOH-terminal deletion mutants and a construct in which all three cysteines in transmembrane regions were substituted. Only the NH2-terminal deletion construct gave rise to currents that activated slowly and displayed MMTS-insensitive kinetics. These results show that the NH2-terminal tail of Kv2.1 participates in transitions leading to activation through interactions involving reduced cysteine(s) that can be modulated from the cytoplasmic phase.",
keywords = "Chemical modification, Cysteine, Electrophysiology, Site-directed mutagenesis",
author = "Pascual, {Juan M.} and Shieh, {Char Chang} and Kirsch, {Glenn E.} and Brown, {Arthur M.}",
year = "1997",
language = "English (US)",
volume = "273",
journal = "American Journal of Physiology - Heart and Circulatory Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "6 42-6",

}

TY - JOUR

T1 - Contribution of the NH2 terminus of Kv2.1 to channel activation

AU - Pascual, Juan M.

AU - Shieh, Char Chang

AU - Kirsch, Glenn E.

AU - Brown, Arthur M.

PY - 1997

Y1 - 1997

N2 - Opening and closing of voltage-operated channels requires the interaction of diverse structural elements. One approach to the identification of channel domains that participate in gating is to locate the sites of action of modifiers. Covalent reaction of Kv2.1 channels with the neutral, sulfhydryl-specific methylmethanethiosulfonate (MMTS) caused a slowing of channel gating with a predominant effect on the kinetics of activation. These effects were also obtained after intracellular, but not extracellular, application of a charged MMTS analog. Single channel analysis revealed that MMTS acted primarily by prolonging the latency to first opening without substantially affecting gating transitions after the channel first opens and until it inactivates. To localize the channel cysteine(s) with which MMTS reacts, we generated NH2- and COOH-terminal deletion mutants and a construct in which all three cysteines in transmembrane regions were substituted. Only the NH2-terminal deletion construct gave rise to currents that activated slowly and displayed MMTS-insensitive kinetics. These results show that the NH2-terminal tail of Kv2.1 participates in transitions leading to activation through interactions involving reduced cysteine(s) that can be modulated from the cytoplasmic phase.

AB - Opening and closing of voltage-operated channels requires the interaction of diverse structural elements. One approach to the identification of channel domains that participate in gating is to locate the sites of action of modifiers. Covalent reaction of Kv2.1 channels with the neutral, sulfhydryl-specific methylmethanethiosulfonate (MMTS) caused a slowing of channel gating with a predominant effect on the kinetics of activation. These effects were also obtained after intracellular, but not extracellular, application of a charged MMTS analog. Single channel analysis revealed that MMTS acted primarily by prolonging the latency to first opening without substantially affecting gating transitions after the channel first opens and until it inactivates. To localize the channel cysteine(s) with which MMTS reacts, we generated NH2- and COOH-terminal deletion mutants and a construct in which all three cysteines in transmembrane regions were substituted. Only the NH2-terminal deletion construct gave rise to currents that activated slowly and displayed MMTS-insensitive kinetics. These results show that the NH2-terminal tail of Kv2.1 participates in transitions leading to activation through interactions involving reduced cysteine(s) that can be modulated from the cytoplasmic phase.

KW - Chemical modification

KW - Cysteine

KW - Electrophysiology

KW - Site-directed mutagenesis

UR - http://www.scopus.com/inward/record.url?scp=0031306025&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031306025&partnerID=8YFLogxK

M3 - Article

C2 - 9435489

AN - SCOPUS:0031306025

VL - 273

JO - American Journal of Physiology - Heart and Circulatory Physiology

JF - American Journal of Physiology - Heart and Circulatory Physiology

SN - 0363-6135

IS - 6 42-6

ER -