The beta subunit of the high conductance calcium-activated potassium channel. Identification of residues involved in charybdotoxin binding.

The Journal of Biological Chemistry
M HannerM L Garcia

Abstract

Coexpression of alpha and beta subunits of the high conductance Ca2+-activated K+ (maxi-K) channel leads to a 50-fold increase in the affinity for 125I-charybdotoxin (125I-ChTX) as compared with when the alpha subunit is expressed alone (Hanner, M., Schmalhofer, W. A., Munujos, P., Knaus, H.-G., Kaczorowski, G. J., and Garcia, M. L. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 2853-2858). To identify those residues in the beta subunit that are responsible for this change in binding affinity, Ala scanning mutagenesis was carried out along the extracellular loop of beta, and the resulting effects on 125I-ChTX binding were determined after coexpression with the alpha subunit. Mutagenesis of each of the four Cys residues present in the loop causes a large reduction in toxin binding affinity, suggesting that these residues could be forming disulfide bridges. The existence of two disulfide bridges in the extracellular loop of beta was demonstrated after comparison of reactivities of native beta and single-Cys-mutated subunits to N-biotin-maleimide. Negatively charged residues in the loop of beta, when mutated individually or in combinations, had no effect on toxin binding with the exception of Glu94, whose alteration modifies kinetics ...Continue Reading

References

Jan 1, 1991·Methods in Enzymology·P A Kolodziej, R A Young
Jan 1, 1995·Biophysical Journal·H G Hansma
Aug 20, 1996·Proceedings of the National Academy of Sciences of the United States of America·J Tseng-CrankP H Reinhart
Dec 10, 1996·Proceedings of the National Academy of Sciences of the United States of America·M WallnerL Toro
Apr 1, 1997·Proceedings of the National Academy of Sciences of the United States of America·M HannerM L Garcia

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Citations

May 6, 2010·Cellular and Molecular Neurobiology·Mikhail SalzmannChristian Derst
Jul 6, 2002·European Journal of Pharmacology·Wen-Fei Chiou, Chieh-Fu Chen
Aug 2, 2008·Proceedings of the National Academy of Sciences of the United States of America·Guoxia LiuSteven O Marx
Sep 29, 2004·The Journal of General Physiology·Lindsey Ciali SantarelliToshinori Hoshi
Dec 14, 2011·The Journal of General Physiology·Aleksandra GruslovaBin Wang
Jul 22, 1999·Annals of the New York Academy of Sciences·W A CoetzeeB Rudy
Apr 2, 2004·The Journal of Clinical Investigation·José M Fernández-FernándezMiguel A Valverde
Jul 5, 2013·The Journal of Neuroscience : the Official Journal of the Society for Neuroscience·Xiaohui SunJianmin Cui
Feb 18, 2011·The Journal of Neuroscience : the Official Journal of the Society for Neuroscience·Cristina Velázquez-MarreroSteven N Treistman
May 3, 2000·Proceedings of the National Academy of Sciences of the United States of America·P MeeraL Toro
Oct 26, 2013·Pflügers Archiv : European journal of physiology·Ana I Fernández-MariñoJosé M Fernández-Fernández
Aug 20, 2015·Biomolecules·Anton HermannThomas M Weiger
Feb 7, 2015·PloS One·Ana Isabel Fernández-MariñoJosé M Fernández-Fernández
Jul 2, 2011·Animal Reproduction Science·Soumen ChoudhurySantosh Kumar Mishra
Oct 12, 2010·Seminars in Cell & Developmental Biology·Uwe SchulteBernd Fakler
Dec 17, 2005·Pharmacology & Therapeutics·Srinivas GhattaStephen T O'Rourke
Aug 24, 2000·The Journal of Biological Chemistry·A L PerrierE Krejci
Apr 14, 2005·The Journal of Biological Chemistry·Guillermo J Pérez
Jun 1, 2005·American Journal of Physiology. Heart and Circulatory Physiology·Deepa NagarCharles R Rosenfeld
Oct 28, 2014·Frontiers in Physiology·Yolima P TorresRamón Latorre
Apr 16, 2010·Physiological Reviews·Olaf Pongs, Jürgen R Schwarz
Dec 10, 2019·ELife·Xiao Tao, Roderick MacKinnon
Nov 4, 2016·Physiological Reviews·Ramon LatorreOsvaldo Alvarez
Apr 3, 2004·American Journal of Physiology. Heart and Circulatory Physiology·Joseph R H Mauban, W Gil Wier
Jul 27, 1999·Current Opinion in Chemical Biology·G J Kaczorowski, M L Garcia

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