An Engineered Cysteine in the External Mouth of a K+ Channel Allows Inactivation to Be Modulated by Metal Binding

Overview

Journal Biophys J

Publisher Cell Press

Specialty Biophysics

Date 1994 Apr 1

PMID 8038379

Citations 167

Authors

G Yellen

D Sodickson

T Y Chen

M E Jurman

Affiliations

Soon will be listed here.

Abstract

Substitution of a cysteine in the extracellular mouth of the pore of the Shaker-delta K+ channel permits allosteric inhibition of the channel by Zn2+ or Cd2+ ions at micromolar concentrations. Cd2+ binds weakly to the open state but drives the channel into the slow (C-type) inactivated state, which has a Kd for Cd2+ of approximately 0.2 microM. There is a 45,000-fold increase in affinity when the channel changes from open to inactivated. These results indicate that C-type inactivation involves a structural change in the external mouth of the pore. This structural change is reflected in the T449C mutant as state-dependent metal affinity, which may result either from a change in proximity of the introduced cysteine residues of the four subunits or from a change of the exposure of this residue on the surface of the protein.

Citing Articles

Stability of N-type inactivation and the coupling between N-type and C-type inactivation in the Aplysia Kv1 channel.

Iwamuro T, Itohara K, Furukawa Y Pflugers Arch. 2024; 476(10):1493-1516.

PMID: 39008084 PMC: 11639194. DOI: 10.1007/s00424-024-02982-5.

Dilation of ion selectivity filters in cation channels.

Huffer K, Tan X, Fernandez-Marino A, Dhingra S, Swartz K Trends Biochem Sci. 2024; 49(5):417-430.

PMID: 38514273 PMC: 11069442. DOI: 10.1016/j.tibs.2024.02.004.

Redox-dependent Cd inhibition of BK-type Ca-activated K channels.

Zhang G, Yang H, Wang Y, Liang H, Shi J, Cui J Biophys J. 2024; 123(14):2076-2084.

PMID: 38400542 PMC: 11309971. DOI: 10.1016/j.bpj.2024.02.015.

Resurgent current in context: Insights from the structure and function of Na and K channels.

Aman T, Raman I Biophys J. 2023; 123(14):1924-1941.

PMID: 38130058 PMC: 11309984. DOI: 10.1016/j.bpj.2023.12.016.

Eukaryotic Kv channel Shaker inactivates through selectivity filter dilation rather than collapse.

Stix R, Tan X, Bae C, Fernandez-Marino A, Swartz K, Faraldo-Gomez J Sci Adv. 2023; 9(49):eadj5539.

PMID: 38064553 PMC: 10708196. DOI: 10.1126/sciadv.adj5539.

References

Kunkel T . Rapid and efficient site-specific mutagenesis without phenotypic selection. Proc Natl Acad Sci U S A. 1985; 82(2):488-92. PMC: 397064. DOI: 10.1073/pnas.82.2.488. View

Changeux J, Devillers-Thiery A, Chemouilli P . Acetylcholine receptor: an allosteric protein. Science. 1984; 225(4668):1335-45. DOI: 10.1126/science.6382611. View

Falke J, Koshland Jr D . Global flexibility in a sensory receptor: a site-directed cross-linking approach. Science. 1987; 237(4822):1596-600. DOI: 10.1126/science.2820061. View

Wallick E, Schwartz A . Interaction of cardiac glycosides with Na+,K+-ATPase. Methods Enzymol. 1988; 156:201-13. DOI: 10.1016/0076-6879(88)56022-6. View

Falke J, Dernburg A, Sternberg D, Zalkin N, Milligan D, Koshland Jr D . Structure of a bacterial sensory receptor. A site-directed sulfhydryl study. J Biol Chem. 1988; 263(29):14850-8. View

Altenbach C, Flitsch S, Khorana H, Hubbell W . Structural studies on transmembrane proteins. 2. Spin labeling of bacteriorhodopsin mutants at unique cysteines. Biochemistry. 1989; 28(19):7806-12. DOI: 10.1021/bi00445a042. View

Wei A, Covarrubias M, Butler A, Baker K, Pak M, Salkoff L . K+ current diversity is produced by an extended gene family conserved in Drosophila and mouse. Science. 1990; 248(4955):599-603. DOI: 10.1126/science.2333511. View

Mackinnon R, Yellen G . Mutations affecting TEA blockade and ion permeation in voltage-activated K+ channels. Science. 1990; 250(4978):276-9. DOI: 10.1126/science.2218530. View

Hoshi T, Zagotta W, Aldrich R . Biophysical and molecular mechanisms of Shaker potassium channel inactivation. Science. 1990; 250(4980):533-8. DOI: 10.1126/science.2122519. View

10.

Smart T . Uncultured lobster muscle, cultured neurons and brain slices: the neurophysiology of zinc. J Pharm Pharmacol. 1990; 42(6):377-87. DOI: 10.1111/j.2042-7158.1990.tb06576.x. View

11.

Pak M, Covarrubias M, Ratcliffe A, Salkoff L . A mouse brain homolog of the Drosophila Shab K+ channel with conserved delayed-rectifier properties. J Neurosci. 1991; 11(3):869-80. PMC: 6575340. View

12.

Mackinnon R . Determination of the subunit stoichiometry of a voltage-activated potassium channel. Nature. 1991; 350(6315):232-5. DOI: 10.1038/350232a0. View

13.

Schild L, Moczydlowski E . Competitive binding interaction between Zn2+ and saxitoxin in cardiac Na+ channels. Evidence for a sulfhydryl group in the Zn2+/saxitoxin binding site. Biophys J. 1991; 59(3):523-37. PMC: 1281218. DOI: 10.1016/S0006-3495(91)82269-X. View

14.

Choi K, Aldrich R, Yellen G . Tetraethylammonium blockade distinguishes two inactivation mechanisms in voltage-activated K+ channels. Proc Natl Acad Sci U S A. 1991; 88(12):5092-5. PMC: 51817. DOI: 10.1073/pnas.88.12.5092. View

15.

Hoshi T, Zagotta W, Aldrich R . Two types of inactivation in Shaker K+ channels: effects of alterations in the carboxy-terminal region. Neuron. 1991; 7(4):547-56. DOI: 10.1016/0896-6273(91)90367-9. View

16.

Araque A, Buno W . Novel inward rectifier blocked by Cd2+ in crayfish muscle. Brain Res. 1991; 563(1-2):321-4. DOI: 10.1016/0006-8993(91)91555-f. View

17.

Pardo L, Heinemann S, Terlau H, Ludewig U, Lorra C, Pongs O . Extracellular K+ specifically modulates a rat brain K+ channel. Proc Natl Acad Sci U S A. 1992; 89(6):2466-70. PMC: 48679. DOI: 10.1073/pnas.89.6.2466. View

18.

Heginbotham L, Mackinnon R . The aromatic binding site for tetraethylammonium ion on potassium channels. Neuron. 1992; 8(3):483-91. DOI: 10.1016/0896-6273(92)90276-j. View

19.

Satin J, KYLE J, Chen M, Bell P, Cribbs L, Fozzard H . A mutant of TTX-resistant cardiac sodium channels with TTX-sensitive properties. Science. 1992; 256(5060):1202-5. DOI: 10.1126/science.256.5060.1202. View

20.

Backx P, Yue D, LAWRENCE J, Marban E, Tomaselli G . Molecular localization of an ion-binding site within the pore of mammalian sodium channels. Science. 1992; 257(5067):248-51. DOI: 10.1126/science.1321496. View