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Inward rectification induced by mono- and diaminoalkane application to inside-out membrane patches was studied in Kir2.1 (IRK1) channels expressed in Xenopus oocytes. Both monoamines and diamines block Kir2.1 channels, with potency increasing as the alkyl chain length increases (from 2 to 12 methylene groups), indicating a strong hydrophobic interaction(More)
ATP-sensitive potassium (KATP) channels link cellular metabolism to electrical activity in nerve, muscle, and endocrine tissues. They are formed as a functional complex of two unrelated subunits-a member of the Kir inward rectifier potassium channel family, and a sulfonylurea receptor (SUR), a member of the ATP-binding cassette transporter family, which(More)
KATP channels are a functional complex of sulphonylurea receptor (SUR1, SUR2) and inward rectifier K+ (Kir6.1, Kir6.2) channel subunits. We have studied the role of the putative pore forming subunit (Kir6.2) in regulation of rectification and gating of KATP channels generated by transfection of SUR1 and Kir6.2 cDNAs in COSm6 cells. In the absence of(More)
KATP channels were reconstituted in COSm6 cells by coexpression of the sulfonylurea receptor SUR1 and the inward rectifier potassium channel Kir6.2. The role of the two nucleotide binding folds of SUR1 in regulation of KATP channel activity by nucleotides and diazoxide was investigated. Mutations in the linker region and the Walker B motif (Walker, J.E.,(More)
Approximately half of the NH(2) terminus of inward rectifier (Kir) channels can be deleted without significant change in channel function, but activity is lost when more than approximately 30 conserved residues before the first membrane spanning domain (M1) are removed. Systematic replacement of the positive charges in the NH(2) terminus of Kir6.2 with(More)
Based initially on their prominence in the squid giant axon, their useful pharmacology, and subsequently on being the first cloned K channels, voltage-gated K (Kv) channels have received the lion's share of attention to their biophysical properties. Kv and Ca-activated K channel kinetics and gating mechanisms have been analyzed , and modeled, in exquisite(More)
is proposed as a critical link in the pathway of glucose-induced insulin release (Cook et al. is high, inhibition of pancreatic K ATP channels due to a Washington University School of Medicine high intracellular [ATP]/[ADP] ratio is presumed to depo-St. Louis, Missouri 63110 larize the plasma membrane, leading to Ca 2ϩ entry † Department of Pediatrics(More)
abstract The sensitivity of K ATP channels to high-affinity block by sulfonylureas and to stimulation by K ϩ channel openers and MgADP (PCOs) is conferred by the regulatory sulfonylurea receptor (SUR) subunit, whereas ATP inhibits the channel through interaction with the inward rectifier (Kir6.2) subunit. Phosphatidylinositol 4,5-bisphosphate (PIP 2)(More)
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