PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 26631167-4 2016 Besides, physiological polyamines are essential to maintain inward rectification of cardiac potassium channels (Kir2.1). Polyamines 23-33 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 112-118 8865359-1 1996 It is known that the rectification property of the inward rectifier K+ channel, IRK1, is caused by a block of outward current by cytoplasmic Mg2+ and polyamines, and that the voltage dependence of rectification shifts according to the equilibrium potential of K+. Polyamines 150-160 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 80-84 8521810-0 1995 C-terminus determinants for Mg2+ and polyamine block of the inward rectifier K+ channel IRK1. Polyamines 37-46 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 88-92 8789092-3 1996 The aspartate residue in the second putative transmembrane segment of the IRK1 inwardly rectifying K+ channel, previously implicated in inward rectification gating due to cytoplasmic Mg2+ and polyamine block, is found in this study to be crucial for the channel"s ability to distinguish between K+ and Rb+ ions. Polyamines 192-201 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 74-78 29907600-5 2018 By studying Kir2.1, the canonical member of the sKir channel family, we first show that the outward currents of Kir2.1 are observed under the external K+-free condition when its inward rectification is reduced and that the complete inhibition of the currents at 0 [K+]out results solely from pore blockade caused by the polyamines. Polyamines 320-330 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 12-18 29907600-5 2018 By studying Kir2.1, the canonical member of the sKir channel family, we first show that the outward currents of Kir2.1 are observed under the external K+-free condition when its inward rectification is reduced and that the complete inhibition of the currents at 0 [K+]out results solely from pore blockade caused by the polyamines. Polyamines 320-330 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 112-118 26631167-5 2016 At membrane potentials more positive than equilibrium potential, intracellular polyamines plug the cytosolic surface of the Kir2.1 so that potassium ions cannot pass through the pore. Polyamines 79-89 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 124-130 26869275-3 2016 In this study, we demonstrated that the major blocking effect of intracellular Mg(2+) on Kir2.1 channels is also closely correlated with K(+) current flow, and the coupled movements of Mg(2+) and K(+) seem to happen in the same flux-coupling segment of the pore as polyamines. Polyamines 265-275 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 89-95 15618275-2 2005 We recently showed that macroscopic Kir2.1 currents obtained from inside-out patches in the presence of various concentrations of cytoplasmic polyamines are well explained by the sum of the currents through two populations of channels that show differing susceptibilities to polyamine blockade. Polyamines 142-152 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 36-42 22371365-1 2012 Outward currents through Kir2.1 channels play crucial roles in controlling the electrical properties of excitable cells, and such currents are subjected to voltage-dependent block by intracellular Mg(2+) and polyamines that bind to both high- and low-affinity sites on the channels. Polyamines 208-218 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 25-31 22371365-2 2012 Under physiological conditions, high-affinity block is saturated and yet outward Kir2.1 currents can still occur, implying that high-affinity polyamine block cannot completely eliminate outward Kir2.1 currents. Polyamines 142-151 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 194-200 22371365-8 2012 This study provides a detailed insight into the mechanism underlying the emergence of outward Kir2.1 currents regulated by inward rectification attributed to high- and low-affinity polyamine blocks. Polyamines 181-190 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 94-100 20713726-0 2010 Flecainide increases Kir2.1 currents by interacting with cysteine 311, decreasing the polyamine-induced rectification. Polyamines 86-95 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 21-27 20713726-4 2010 Flecainide increases outward I(Kir2.1) generated by homotetrameric Kir2.1 channels by decreasing their affinity for intracellular polyamines, which reduces the inward rectification of the current. Polyamines 130-140 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 31-37 20713726-4 2010 Flecainide increases outward I(Kir2.1) generated by homotetrameric Kir2.1 channels by decreasing their affinity for intracellular polyamines, which reduces the inward rectification of the current. Polyamines 130-140 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 67-73 16316973-0 2005 Long polyamines act as cofactors in PIP2 activation of inward rectifier potassium (Kir2.1) channels. Polyamines 5-15 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 83-89 16316973-4 2005 Here we show that polyamines, which cause inward rectification by selectively blocking outward current, also regulate the interaction of PIP2 with Kir2.1 channels to maintain channel availability. Polyamines 18-28 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 147-153 16316973-5 2005 Using spermine and diamines as polyamine analogs, we demonstrate that both spontaneous and PIP2 antibody-induced rundown of Kir2.1 channels in excised inside-out patches was markedly slowed by long polyamines; in contrast, polyamines with shorter chain length were ineffective. Polyamines 31-40 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 124-130 16316973-5 2005 Using spermine and diamines as polyamine analogs, we demonstrate that both spontaneous and PIP2 antibody-induced rundown of Kir2.1 channels in excised inside-out patches was markedly slowed by long polyamines; in contrast, polyamines with shorter chain length were ineffective. Polyamines 198-208 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 124-130 16316973-10 2005 We conclude that long polyamines serve a dual role as both blockers and coactivators (with PIP2) of Kir2.1 channels. Polyamines 22-32 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 100-106 15618275-0 2005 Two Kir2.1 channel populations with different sensitivities to Mg(2+) and polyamine block: a model for the cardiac strong inward rectifier K(+) channel. Polyamines 74-83 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 4-10 15618275-1 2005 The strong inward rectification of the whole cell Kir2.1 current, which is very similar to the cardiac inward rectifier K(+) current (I(K1)), is caused by voltage-dependent blockade of outward currents by the intracellular polyamines spermine and spermidine. Polyamines 223-233 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 50-56 17635958-1 2007 Steeply voltage-dependent block by intracellular polyamines underlies the strong inward rectification properties of Kir2.1 and other Kir channels. Polyamines 49-59 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 116-122 16109731-0 2005 A difference in inward rectification and polyamine block and permeation between the Kir2.1 and Kir3.1/Kir3.4 K+ channels. Polyamines 41-50 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 84-90 16109731-4 2005 We show that Kir3.1/Kir3.4 is more sensitive to extracellular spermine block than Kir2.1, and that intracellular and extracellular polyamines can permeate Kir3.1/Kir3.4, but not Kir2.1, to a limited extent. Polyamines 131-141 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 178-184 16109731-5 2005 We describe a simple kinetic model in which polyamines act as permeant blockers of Kir3.1/Kir3.4, but as relatively impermeant blockers of Kir2.1. Polyamines 44-54 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 139-145 16109731-7 2005 This suggests that Kir3.1/Kir3.4 exhibits weaker inward rectification than Kir2.1 because of the difference in the balance of polyamine block and permeation of the two channels. Polyamines 126-135 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 75-81 15618275-2 2005 We recently showed that macroscopic Kir2.1 currents obtained from inside-out patches in the presence of various concentrations of cytoplasmic polyamines are well explained by the sum of the currents through two populations of channels that show differing susceptibilities to polyamine blockade. Polyamines 142-151 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 36-42 12642596-3 2003 To understand the mechanism by which polyamines cause rectification, we examined IRK1 (Kir2.1) block by a series of bis-alkyl-amines (bis-amines) and mono-alkyl-amines (mono-amines) of varying length. Polyamines 37-47 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 81-85 14724206-0 2004 Two modes of polyamine block regulating the cardiac inward rectifier K+ current IK1 as revealed by a study of the Kir2.1 channel expressed in a human cell line. Polyamines 13-22 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 114-120 14724206-7 2004 The extra conductances, which generated most of the outward currents in the presence of 5-10 microm spermine or 10-100 microm spermidine, were quantitatively explained by a model that considered two populations of Kir2.1 channels, which were blocked by polyamines in either a high-affinity mode (Mode 1 channel) or a low-affinity mode (Mode 2 channel). Polyamines 253-263 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 214-220 11004205-1 2000 The IRK1 channel is inhibited by intracellular cations such as Mg(2+) and polyamines in a voltage-dependent manner, which renders its I-V curve strongly inwardly rectifying. Polyamines 74-84 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 4-8 10828252-0 2000 Mechanism of IRK1 channel block by intracellular polyamines. Polyamines 49-59 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 13-17 10828252-1 2000 Intracellular polyamines inhibit the strongly rectifying IRK1 potassium channel by a mechanism different from that of a typical ionic pore blocker such as tetraethylammonium. Polyamines 14-24 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 57-61 10828252-4 2000 Furthermore, contrary to the expectation for a nonpermeant ionic pore blocker, a significant residual IRK1 current persists at very positive membrane voltages; the amplitude of the residual current decreases with increasing polyamine concentration. Polyamines 224-233 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 102-106 10828252-5 2000 This complex blocking behavior of polyamines can be accounted for by a minimal model whereby intracellular polyamines inhibit the IRK1 channel by inducing two blocked channel states. Polyamines 34-44 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 130-134 10828252-5 2000 This complex blocking behavior of polyamines can be accounted for by a minimal model whereby intracellular polyamines inhibit the IRK1 channel by inducing two blocked channel states. Polyamines 107-117 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 130-134 10828252-7 2000 The proposal that polyamines traverse the pore at finite rates is supported by the observation that philanthotoxin-343 (spermine with a bulky chemical group attached to one end) acts as a nonpermeant ionic blocker in the IRK1 channel. Polyamines 18-28 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 221-225 10102936-0 1999 Novel gating mechanism of polyamine block in the strong inward rectifier K channel Kir2.1. Polyamines 26-35 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 83-89 10102936-2 1999 Previous studies have attributed the rectification properties of strong inward rectifiers such as Kir2.1 to voltage-dependent binding of intracellular polyamines or Mg to the pore (direct open channel block), thereby preventing outward passage of K ions. Polyamines 151-161 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 98-104 10102936-3 1999 We have studied interactions between polyamines and the polyamine toxins philanthotoxin and argiotoxin on inward rectification in Kir2.1. Polyamines 37-47 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 130-136 10102936-3 1999 We have studied interactions between polyamines and the polyamine toxins philanthotoxin and argiotoxin on inward rectification in Kir2.1. Polyamines 37-46 potassium inwardly rectifying channel subfamily J member 2 Homo sapiens 130-136