Potassium channel block by cytoplasmic polyamines as the mechanism of intrinsic rectification
- PMID: 7969496
- DOI: 10.1038/372366a0
Potassium channel block by cytoplasmic polyamines as the mechanism of intrinsic rectification
Abstract
Inwardly rectifying potassium channels conduct ions more readily in the inward than the outward direction, an essential property for normal electrical activity. Although voltage-dependent block by internal magnesium ions may underlie inward rectification in some channels, an intrinsic voltage-dependent closure of the channel plays a contributory, or even exclusive, role in others. Here we report that, rather than being intrinsic to the channel protein, so-called intrinsic rectification of strong inward rectifiers requires soluble factors that are not Mg2+ and can be released from Xenopus oocytes and other cells. Biochemical and biophysical characterization identifies these factors as polyamines (spermine, spermidine, putrescine and cadaverine). The results suggest that intrinsic rectification results from voltage-dependent block of the channel pore by polyamines, not from a voltage sensor intrinsic to the channel protein.
Similar articles
-
The mechanism of inward rectification of potassium channels: "long-pore plugging" by cytoplasmic polyamines.J Gen Physiol. 1995 Nov;106(5):923-55. doi: 10.1085/jgp.106.5.923. J Gen Physiol. 1995. PMID: 8648298 Free PMC article.
-
Electrostatics in the cytoplasmic pore produce intrinsic inward rectification in kir2.1 channels.J Gen Physiol. 2005 Dec;126(6):551-62. doi: 10.1085/jgp.200509367. J Gen Physiol. 2005. PMID: 16316974 Free PMC article.
-
Functional roles of charged amino acid residues on the wall of the cytoplasmic pore of Kir2.1.J Gen Physiol. 2006 Apr;127(4):401-19. doi: 10.1085/jgp.200509434. Epub 2006 Mar 13. J Gen Physiol. 2006. PMID: 16533896 Free PMC article.
-
Mechanism of rectification in inward-rectifier K+ channels.Annu Rev Physiol. 2004;66:103-29. doi: 10.1146/annurev.physiol.66.032102.150822. Annu Rev Physiol. 2004. PMID: 14977398 Review.
-
Inward rectifier potassium channels.Annu Rev Physiol. 1997;59:171-91. doi: 10.1146/annurev.physiol.59.1.171. Annu Rev Physiol. 1997. PMID: 9074760 Review.
Cited by
-
Cooperative Gating of a K+ Channel by Unmodified Biological Anionic Lipids Viewed by Solid-State NMR Spectroscopy.J Am Chem Soc. 2024 Feb 21;146(7):4421-4432. doi: 10.1021/jacs.3c09266. Epub 2024 Feb 9. J Am Chem Soc. 2024. PMID: 38334076 Free PMC article.
-
Polyamine catabolism in carcinogenesis: potential targets for chemotherapy and chemoprevention.Amino Acids. 2014 Mar;46(3):511-9. doi: 10.1007/s00726-013-1529-6. Epub 2013 Jun 15. Amino Acids. 2014. PMID: 23771789 Free PMC article. Review.
-
Inner activation gate in S6 contributes to the state-dependent binding of cAMP in full-length HCN2 channel.J Gen Physiol. 2012 Jul;140(1):29-39. doi: 10.1085/jgp.201110749. Epub 2012 Jun 11. J Gen Physiol. 2012. PMID: 22689828 Free PMC article.
-
A difference in inward rectification and polyamine block and permeation between the Kir2.1 and Kir3.1/Kir3.4 K+ channels.J Physiol. 2005 Nov 1;568(Pt 3):749-66. doi: 10.1113/jphysiol.2005.085746. Epub 2005 Aug 18. J Physiol. 2005. PMID: 16109731 Free PMC article.
-
Relaxant Effect of Spermidine on Acethylcholine and High K-induced Gastric Contractions of Guinea-Pig.Korean J Physiol Pharmacol. 2008 Apr;12(2):59-64. doi: 10.4196/kjpp.2008.12.2.59. Epub 2008 Apr 30. Korean J Physiol Pharmacol. 2008. PMID: 20157395 Free PMC article.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Other Literature Sources
Molecular Biology Databases