ArticleThe Journal of membrane biology1993
Ca2+ activation and pH dependence of a maxi K+ channel from rabbit distal colon epithelium.
Article in The Journal of membrane biology, 1993. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers, 1 of them a synthesis that pooled it.
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Who cites it
13 citing papers in PubMed, 1 synthesis or guideline pooled it, 39 citations in OpenAlex.
- Potassium channels in intestinal epithelial cells and their pharmacological modulation: a systematic review.American journal of physiology. Cell physiology · 2021Pooled it
- Cancer-associated loss-of-function mutations in KCNQ1 enhance Wnt/β-catenin signalling disrupting epithelial homeostasis.Oncogene · 2025Article
- Regulation of BK Channels by Beta and Gamma Subunits.Annual review of physiology · 2019Review
- Native and recombinant Slc26a3 (downregulated in adenoma, Dra) do not exhibit properties of 2Cl-/1HCO3- exchange.American journal of physiology. Cell physiology · 2011Article
- Potassium channels in epithelial transport.Pflugers Archiv : European journal of physiology · 2003Review
- Localization of Ca2+ -activated big-conductance K+ channels in rabbit distal colon.Pflugers Archiv : European journal of physiology · 2003Article
- Identification and function of type-2 and type-3 ryanodine receptors in gut epithelial cells.The Biochemical journal · 1996Article
- Ca2+ regulated K+ and non-selective cation channels in the basolateral membrane of rat colonic crypt base cells.Pflugers Archiv : European journal of physiology · 1996Article
- The membrane transporters regulating epithelial NaCl secretion.Pflugers Archiv : European journal of physiology · 1996Review
- The cAMP-regulated and 293B-inhibited K+ conductance of rat colonic crypt base cells.Pflugers Archiv : European journal of physiology · 1996Article
- Maxi K+ channels in the basolateral membrane of the exocrine frog skin gland regulated by intracellular calcium and pH.Pflugers Archiv : European journal of physiology · 1995Article
- pH- and voltage-dependent conductances in toad skin.The Journal of membrane biology · 1995Article
- Neurogenic chloride secretion induced by scorpion venom and veratrine in rabbit colon.Naunyn-Schmiedeberg's archives of pharmacology · 1994Article
Corrections and comments
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Authors and funding
4 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
To determine if their properties are consistent with a role in regulation of transepithelial transport, Ca(2+)-activated K+ channels from the basolateral plasma membrane of the surface cells in the distal colon have been characterized by single channel analysis after fusion of vesicles with planar lipid bilayers. A Ca(2+)-activated K+ channel with a single channel conductance of 275 pS was predominant. The sensitivity to Ca2+ was strongly dependent on the membrane potential and on the pH. At a neutral pH, the K0.5 for Ca2+ was raised from 20 nM at a potential of 0 mV to 300 nM at -40 mV. A decrease in pH at the cytoplasmic face of the K+ channel reduced the Ca2+ sensitivity dramatically. A loss of the high sensitivity to Ca2+ was also observed after incubation with MgCl2, possibly a result of dephosphorylation of the channels by endogenous phosphatases. Modification of the channel protein may thus explain the variation in Ca2+ sensitivity between studies on K+ channels from the same tissue. High affinity inhibition (K0.5 = 10 nM) by charybdotoxin of the Ca(2+)-activated K+ channel from the extracellular face could be lifted by an outward flux of K+ through the channel. However, at the ion gradients and potentials found in the intact epithelium, charybdotoxin should be a useful tool for examination of the role of maxi K+ channels. The high sensitivity for Ca2+ and the properties of the activator site are in agreement with an important regulatory role for the high conductance K+ channel in the epithelial cells.
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