| 1997 |
Kir6.1 forms a functional K+ channel with SUR2B that is activated by nucleotide diphosphates (UDP, GDP) and K+ channel openers (pinacidil, nicorandil), inhibited by glibenclamide, but not inhibited by intracellular ATP alone — making it an NDP-dependent rather than classical ATP-sensitive K+ channel. Intracellular ATP on its own activated rather than inhibited the channel. |
Patch-clamp electrophysiology (cell-attached and inside-out configurations) in HEK293T cells co-transfected with SUR2B and Kir6.1 |
The Journal of physiology |
High |
9130167
|
| 1996 |
SUR1 is required to confer both diazoxide sensitivity and ATP sensitivity on Kir6.1; Kir6.1 expressed alone in HEK293 cells shows currents unaffected by diazoxide or intracellular ATP, but Kir6.1+SUR1 co-expression produces diazoxide-activated and ATP-regulated currents. |
Whole-cell patch-clamp in HEK293 cells transfected with Kir6.1 alone or co-transfected with Kir6.1 and SUR1 |
The Journal of physiology |
High |
8865068
|
| 2002 |
Kir6.1 knockout mice develop spontaneous ST elevation, atrioventricular block, and sudden death resembling Prinzmetal angina; vascular smooth muscle cells from knockout mice lack pinacidil-induced K+ currents and vasodilation, establishing Kir6.1 as the pore-forming subunit of the vascular KATP channel critical for coronary artery tone regulation. |
Gene knockout mouse model; patch-clamp of vascular smooth muscle cells; ECG recordings; pharmacological vasodilation assays; methylergometrine challenge |
Nature medicine |
High |
11984590
|
| 1997 |
Kir6.1 protein localizes predominantly to mitochondria (inner membrane) in rat skeletal muscle, cardiac muscle, liver, and pancreas, as well as weakly to plasma membrane, suggesting it may be a subunit of the mitochondrial ATP-sensitive K+ channel. |
Immunoblot of subcellular fractions, immunofluorescence staining, and immunoelectron microscopy with anti-Kir6.1 antibody |
Biochemical and biophysical research communications |
Medium |
9434770
|
| 2007 |
Antibody-based immunoblot signals previously attributed to Kir6.1 in heart mitochondria were identified by LC-MS/MS as NADH-dehydrogenase flavoprotein 1 (51 kDa band) and mitochondrial isocitrate dehydrogenase (48 kDa band), not Kir6.1; these results argue against Kir6.1 being a subunit of the mitochondrial KATP channel based on immunoreactivity alone. |
Immunoblot, immunogold electron microscopy, immunofluorescence, 1D/2D/native gel, LC-MS/MS protein identification from isolated heart mitochondria |
Biochemical and biophysical research communications |
High |
18068667
|
| 2001 |
Kir6.1 (not Kir6.2) is the principal pore-forming subunit of KATP channels in astrocytes, localizing to distal perisynaptic and peridendritic astrocyte plasma membrane processes; functional KATP channels confirmed in Bergmann glial cells by slice patch-clamp. |
Immunocytochemistry with subunit-specific antibodies, ultrastructural immunoelectron microscopy, slice patch-clamp electrophysiology |
Molecular and cellular neurosciences |
High |
11749042
|
| 2004 |
In primary human coronary artery endothelial cells (HCAEC), KATP channels form a heteromultimeric complex of Kir6.1, Kir6.2, and SUR2B subunits, as demonstrated by reciprocal co-immunoprecipitation and co-localization at the cell surface membrane. |
Reciprocal co-immunoprecipitation, Western blotting, confocal microscopy immunofluorescence in primary human cells |
Journal of molecular and cellular cardiology |
High |
15380676
|
| 2000 |
Dominant-negative Kir6.1 suppresses SUR2B+Kir6.1 currents but has no effect on SUR2A+Kir6.2 currents in A549 cells; dominant-negative Kir6.2 has no effect on endogenous KATP current in rabbit ventricular myocytes while dominant-negative Kir6.2 suppresses it, providing functional evidence that Kir6.1 and Kir6.2 do not heteromultimerize and that Kir6.2 is the sole pore-forming subunit of surface KATP channels in cardiac myocytes. |
Adenoviral dominant-negative gene transfer, whole-cell patch-clamp in A549 cells and rabbit ventricular myocytes |
The Journal of biological chemistry |
High |
10837494
|
| 2006 |
Knockout of KCNJ8 (Kir6.1) predisposes mice to fatal endotoxic shock by impairing coronary vasodilation in response to cytokine/metabolic signals during LPS-induced sepsis; K+ channel opener treatment improved survival in wild-type but not knockout mice, establishing Kir6.1 as a vascular metabolic sensor for cardiovascular homeostasis in sepsis. |
Kir6.1 knockout mice, LPS endotoxin model, survival analysis, assessment of cardiac activity and coronary vasodilation, pharmacological rescue with K+ channel opener |
FASEB journal |
High |
17077304
|
| 2010 |
The KCNJ8-S422L missense mutation causes a gain-of-function in the cardiac Kir6.1 KATP channel with increased current over 0–40 mV range when co-expressed with SUR2A; this gain-of-function is a pathogenic mechanism for J-wave syndromes (Brugada syndrome and early repolarization syndrome). |
Site-directed mutagenesis, heterologous expression in COS-1 cells with SUR2A, whole-cell patch-clamp |
Heart rhythm |
High |
20558321
|
| 2011 |
The S422L gain-of-function of Kir6.1/KATP channel is due to reduced sensitivity to intracellular ATP (IC50 785.5 μM for mutant vs. 38.4 μM for WT), resulting in incomplete channel closure under normoxic conditions; the current increase is ~2-fold in whole-cell recordings with SUR2A. |
Whole-cell and inside-out patch-clamp in TSA201 cells co-expressing KCNJ8 variants with SUR2A, direct sequencing |
Heart rhythm |
High |
22056721
|
| 2014 |
A de novo Kir6.1[C176S] (p.Cys176Ser) missense mutation causes Cantú syndrome via markedly increased KATP channel activity due to reduced ATP sensitivity, whether co-expressed with SUR1 or SUR2A, establishing KCNJ8 as a causal gene for Cantú syndrome and implicating gain of KATP channel function as the cardinal disease mechanism. |
Candidate gene screening, heterologous expression of Kir6.1[C176S] with SUR1 or SUR2A, patch-clamp electrophysiology, ATP sensitivity assays |
Human mutation |
High |
24700710
|
| 2002 |
Protein kinase C (PKC) inhibits Kir6.1/SUR2B channel activity but increases activity of Kir6.2/SUR2B channels; this differential PKC regulation of Kir6.1/SUR2B (but not Kir6.2/SUR2B) mimics native vascular KNDP channels, supporting the composition of vascular KATP channels as Kir6.1/SUR2B homotetramers. |
Patch-clamp electrophysiology in HEK293 cells expressing Kir6.1/SUR2B, Kir6.2/SUR2B, or combined subunits; purified PKC application; PKC inhibitors; phorbol ester controls |
The Journal of physiology |
High |
12015420
|
| 2007 |
PKC-dependent inhibition of the Kir6.1/SUR2B channel is mediated by a motif of four serine phosphorylation repeats (Ser-354, Ser-379, Ser-385, Ser-391, Ser-397) in the distal C-terminus of Kir6.1, plus the proximal N-terminus (structural role in gating). Combined mutation of 5 serines to alanine abolished PKC inhibition; in vitro phosphorylation confirmed 4 serines as direct PKC substrates. |
Kir6.1-Kir6.2 chimeras, site-directed mutagenesis of C-terminal serines, whole-cell patch-clamp in HEK293 cells, in vitro 32P phosphorylation assay with purified PKC |
The Journal of biological chemistry |
High |
18048350
|
| 2007 |
Arginine vasopressin (AVP) inhibits Kir6.1/SUR2B channel current via the Gq-coupled V1a receptor and PKC pathway, suppressing open-state probability without affecting single-channel conductance; this correlates with AVP-induced vasoconstriction in mesenteric arteries that is reversed by pinacidil. |
Whole-cell patch-clamp in HEK293 cells co-expressing Kir6.1/SUR2B and V1a receptor; isolated mesenteric artery recordings; PKC inhibitors; phorbol ester controls |
American journal of physiology. Regulatory, integrative and comparative physiology |
High |
17428891
|
| 2008 |
The intrinsic metabolic sensitivity of Kir6.1/SUR2B channels is not conferred by ATP inhibition of the pore-forming Kir6.1 subunit but rather is a property of the SUR2B regulatory subunit; mutagenesis of key residues in both nucleotide-binding domains (NBDs) of SUR2B implicated both NBDs in governing metabolic sensitivity. |
86Rb efflux assays and patch-clamp in HEK293 and CHO cells expressing Kir6.1/SUR2B with NBD mutagenesis |
Cardiovascular research |
High |
18522960
|
| 2011 |
Loss-of-function KCNJ8 mutations (E332del and V346I) reduce pinacidil-activated KATP current by 40–68% when co-expressed with SUR2A, and were identified in SIDS cases, establishing loss-of-function Kir6.1 mutations as a pathogenic mechanism in SIDS possibly via maladaptive cardiac response to metabolic stress. |
Comprehensive ORF sequencing of SIDS cohort (292 cases), heterologous expression of mutants with SUR2A in COS-1 cells, whole-cell patch-clamp |
Circulation. Cardiovascular genetics |
High |
21836131
|
| 2013 |
Smooth muscle-specific gain-of-function expression of ATP-insensitive Kir6.1[G343D] (and Kir6.1[G343D,Q53R]) in mice causes hypotension, reduced vascular contractility, and elevated basal/pinacidil-activated KATP conductance in mesenteric artery myocytes; conversely, loss of Kir6.1 or smooth muscle dominant-negative expression elevates blood pressure, establishing that Kir6.1 overactivity in vascular smooth muscle directly lowers blood pressure. |
Conditional transgenic mice with tamoxifen-inducible smooth muscle-specific Cre; blood pressure measurement (telemetry and anesthesia); contractility of isolated mesenteric arteries; patch-clamp of isolated myocytes |
Journal of the American Heart Association |
High |
23974906
|
| 2009 |
LPS upregulates Kir6.1 and SUR2B mRNA and protein in vascular smooth muscle cells via NF-κB-dependent signaling, enhancing KATP channel activity and causing hyperpolarization/vasodilation; Toll-like receptor ligands similarly stimulate Kir6.1/SUR2B expression. |
Mesenteric arterial ring contractility assays, whole-cell patch-clamp of aortic smooth myocytes, quantitative PCR, NF-κB inhibitors, heterologous expression controls |
The Journal of biological chemistry |
High |
19959479
|
| 1999 |
Co-expression of Kir6.1 with SUR2B increases the affinity of SUR2B for glibenclamide (KD shifts from ~32 nM for SUR2B alone to ~6 nM for SUR2B/Kir6.1 complex); the K+ channel opener P1075 affinity is unchanged, suggesting Kir6.1 modulates the pharmacology of SUR2B in the assembled channel. |
Radioligand binding experiments and whole-cell voltage-clamp in intact transfected HEK cells |
Molecular pharmacology |
High |
10531400
|
| 2010 |
Kir6.1 protein localizes predominantly to the endoplasmic reticulum (ER), not the mitochondria or plasma membrane, in heterologously expressed and endogenous settings; dominant-negative Kir6.1 constructs significantly reduced amplitude and rate of rise of cytosolic Ca2+ transients, implicating Kir6.1 in modulation of ER Ca2+ release. |
Confocal imaging of Kir6.1-GFP, subcellular fractionation, siRNA knockdown, dominant-negative constructs, Ca2+ imaging in C2C12 muscle cells |
The Journal of membrane biology |
Medium |
20306027
|
| 2017 |
Kir6.1 contains a 'slide helix' where the V65M (Cantú syndrome) substitution, but not V65L, increases open-state stability and markedly reduces ATP sensitivity and glibenclamide sensitivity in both Kir6.1 and the analogous Kir6.2(V64M), revealing a conserved gating mechanism and predicting that sulfonylurea therapy may be ineffective for this CS mutation class. |
Ion flux (86Rb efflux) assays and patch-clamp of Kir6.1/Kir6.2 V65M/V65L mutants co-expressed with various SUR subunits in intact cells and excised patches |
The Journal of biological chemistry |
High |
28842488
|
| 2007 |
Functional Kir6.1/SUR1 channels are located at excitatory presynaptic terminals in hippocampal CA3; genetic deletion of Kir6.1 or SUR1 enhances glutamate release at CA3 synapses and increases seizure susceptibility, establishing Kir6.1/SUR1 as a presynaptic channel that inhibits glutamate release and suppresses epileptiform activity. |
Immunofluorescence co-localization, whole-cell patch-clamp of glutamate release in knockout mice, seizure susceptibility assays |
Journal of neurochemistry |
High |
17883401
|
| 2014 |
Kir6.1 physically interacts with Cx43 in cardiomyocyte mitochondria (H9C2 cells) in a phospho-specific manner; hypoxia increases phosphorylation of Cx43 at Ser262 and increases Cx43-Kir6.1 interaction mediated by PKCε; this interaction prevents mitochondria-mediated hypoxia-induced cell apoptosis. |
Co-immunoprecipitation, co-localization, PKC inhibitor studies, hypoxia model in H9C2 cardiomyocyte cell line |
Cellular signalling |
Medium |
24815185
|
| 2012 |
Kir6.1 interacts with Cx43 in a phospho-specific manner; Cx43 phosphorylated at Ser262 interacts preferentially with Kir6.1; phospho-deficient S262A mutation abolishes the interaction. |
Pulldown, co-immunoprecipitation, and co-localization assays; phospho-deficient mutagenesis |
Experimental cell research |
Medium |
22960107
|
| 2019 |
Kir6.1 physically associates with NLRP3 and inhibits assembly of the NLRP3 inflammasome; Kir6.1 depletion activates NLRP3 inflammasome and worsens insulin resistance in vivo, while Kir6.1 overexpression has opposing effects. |
Co-immunoprecipitation of endogenous Kir6.1-NLRP3 interaction, KO and overexpression in mice and primary cells, inflammasome activation assays, insulin resistance measurements |
Experimental & molecular medicine |
Medium |
31387986
|
| 2022 |
Kir6.1 directly interacts with NLRP3 in astrocytes, preventing assembly and activation of the NLRP3 inflammasome; astrocyte-specific Kir6.1 KO promotes astroglial NF-κB activation and extracellular C3 release, which activates neuronal C3aR to induce neuron death in a PD model. |
Astrocyte-specific Kir6.1 KO mice, LPS-induced PD model, co-immunoprecipitation, NF-κB inhibitor and C3aR antagonist rescue |
Brain, behavior, and immunity |
Medium |
33838249
|
| 2018 |
Kir6.1 deficiency in microglia enhances M1 polarization and p38 MAPK-NF-κB signaling; Kir6.1 overexpression promotes M2 polarization; in vivo, Kir6.1 deficiency exacerbates dopaminergic neuron death via p38 MAPK-NF-κB, and suppression of p38 MAPK partially rescues the phenotype. |
Kir6.1 knockdown/overexpression in microglia, KO mouse PD model (MPTP), p38 MAPK inhibitor in vivo rescue, Western blotting for pathway components |
Cell death & disease |
Medium |
29540778
|
| 2019 |
Astrocytic Kir6.1 KO inhibits mitophagy in astrocytes, resulting in accumulation of damaged mitochondria, increased ROS, and neuroinflammation leading to dopaminergic neuron death; restoration of mitophagy rescues the Kir6.1 KO phenotype. |
Astrocyte-specific Kir6.1 KO mice, MPTP PD model, in vivo and in vitro mitophagy assays, ROS measurement, mitophagy rescue experiments |
Brain, behavior, and immunity |
Medium |
31288070
|
| 2022 |
Kir6.1/ABCC9 K-ATP channel cell-autonomously regulates brain vascular smooth muscle cell (VSMC) differentiation by modulating intracellular Ca2+ oscillations via voltage-dependent calcium channels; Kcnj8 KO mice show defective VSMC development, impaired vasoconstrictive capacity, and neuronal-evoked vasodilation leading to local hyperemia. |
Kcnj8 KO mice, zebrafish chemical/genetic inhibition, cell culture models, Ca2+ imaging, genetic/pharmacological manipulation of K-ATP and voltage-dependent Ca channels |
Developmental cell |
High |
35588738
|
| 2020 |
Kir6.1 and SUR2B form functional KATP channels in lymphatic smooth muscle (LSM); smooth muscle-specific gain-of-function Kir6.1 expression causes profound lymphatic contractile dysfunction and LSM hyperpolarization partially rescued by glibenclamide; lymphatic endothelium-specific Kir6.1 gain-of-function has no effect on contractile function. |
PCR subunit identification, pressure myography, global Kir6.1/SUR2 KO mice, smooth muscle-specific and endothelium-specific Kir6.1 GoF transgenic mice, glibenclamide rescue |
The Journal of physiology |
High |
32372450
|
| 2020 |
Kir6.1/SUR2 subunits underlie KATP channels throughout small intestine and colon smooth muscle; Cantú syndrome knockin mice (KCNJ8 and ABCC9 GoF mutations) exhibit reduced intestinal contractility and GI dysmotility rescued by glibenclamide treatment. |
Kir6.1/SUR2 KO and human CS mutation knockin mice, intestinal contractility assays, GI transit measurement, glibenclamide treatment |
JCI insight |
High |
33170808
|
| 2016 |
Gain-of-function Kir6.1[G343D] or [G343D,Q53R] expressed in pancreatic β cells causes glucose intolerance and diabetes via reduced insulin secretion; native Kir6.1 transcripts are expressed in human and mouse islets, indicating Kir6.1 can be incorporated into pancreatic KATP channels and contribute to insulin secretion control. |
Transgenic mice with β cell-specific (RIP) Kir6.1 GoF expression; BAC transgenic mice; glucose tolerance tests; glucose and sulfonylurea-dependent insulin secretion assays; K+ depolarization controls; qRT-PCR for native Kir6.1 transcripts |
The Journal of general physiology |
High |
27956473
|
| 1999 |
KATP channels in glucose-receptive neurons of the rat ventromedial hypothalamus are composed of Kir6.1 and SUR1 (not Kir6.2 or SUR2), as shown by single-cell RT-PCR; these channels are activated by glucose removal or metabolic inhibition (65 pS), blocked by sulfonylureas, and also activated by diazoxide and leptin fragment, establishing Kir6.1/SUR1 as the glucose-sensing KATP channel in VMH. |
Patch-clamp (cell-attached and whole-cell) in brain slices, single-cell RT-PCR from individually harvested neurons |
The Journal of physiology |
High |
10050011
|
| 2020 |
miR-223, induced by the reactive carbonyl species methylglyoxal (MGO), directly targets the 3'UTR of Kir6.1 mRNA to downregulate its expression; miR-223 overexpression reduces KATP protein, inhibits channel activity, and enhances vasoconstriction; the 3'UTR interaction site was confirmed by mutagenesis luciferase assay. |
miR-223 overexpression/knockdown in smooth muscle cells, luciferase 3'UTR reporter with mutagenesis, qRT-PCR, Western blot, patch-clamp, perfused mesenteric arterial ring assays |
Vascular pharmacology |
High |
32151743
|
| 2000 |
Kir6.1 and Kir6.2 are capable of forming heteromeric KATP channels; when co-expressed with SUR2A, co-transfection produces channels with intermediate conductances (between 33.6 pS for Kir6.1/SUR2A and 67.1 pS for Kir6.2/SUR2A); Kir6.1-6.2 tandem protein forms a channel (58.9 pS) with intermediate conductance and lower MgATP sensitivity than Kir6.2. |
Heterologous co-expression in COS7 cells, single-channel patch-clamp, tandem fusion protein construction |
Pflugers Archiv : European journal of physiology |
Medium |
11007308
|
| 2022 |
Kir6.1 in astrocytes is an essential negative modulator of NLRP3-mediated pyroptosis; Kir6.1 physically associates with NLRP3 and prevents inflammasome assembly and activation; astrocyte-specific Kir6.1 KO increases NLRP3 inflammasome-mediated astrocytic pyroptosis, inducing depressive-like behaviors in mice. |
Astrocyte-specific Kir6.1 KO mice, depression models, co-immunoprecipitation of Kir6.1-NLRP3, NLRP3 inflammasome assembly assays, VX-765 (NLRP3 inhibitor) rescue |
Theranostics |
Medium |
36185602
|
| 2024 |
Kir6.1 (Kcnj8) is required for normal NK cell development; NK cell-specific Kcnj8 ablation results in fewer mature CD27-/CD11b+ and KLRG-1+ NK cells in bone marrow and spleen; patch-clamp confirmed a PNU-37883A-sensitive current in a subset of NK cells. |
NK cell-specific Kcnj8 KO mice, flow cytometry, patch-clamp electrophysiology, transcriptomics |
Frontiers in immunology |
Medium |
39687626
|
| 1998 |
CFTR mediates sulphonylurea block of Kir6.1; Kir6.1 expressed alone in NIH3T3 cells is not blocked by glibenclamide, but co-expression with CFTR confers glibenclamide sensitivity (IC50 ~36 μM); CFTR co-expression does not affect Ba2+ block or single-channel conductance of Kir6.1. |
Heterologous expression in NIH3T3 cells, whole-cell and cell-attached and inside-out patch-clamp |
The Journal of physiology |
Medium |
9490811
|
| 2026 |
A novel KCNJ8-A88G mutation causes a 2-fold gain-of-function in KATP current with increased single-channel conductance (~73 vs ~46 pS), prolonged open state duration, and drastically reduced ATP sensitivity (IC50 ~1702 vs ~44 μM); molecular dynamics suggest A88G releases restriction of residue F131, causing greater separation of selectivity filter residues and increased conductance. |
Whole-cell and inside-out patch-clamp in HEK293 cells, single-channel analysis, Kir6.1 homology modelling and molecular dynamics simulations |
JACC. Clinical electrophysiology |
High |
41995661
|
| 2026 |
Kir6.1-containing KATP channels in ventricular cardiomyocytes are constitutively active and distinct from the canonical Kir6.2/SUR2A channel; cardioprotective stimuli (adenosine, ischaemic preconditioning) increase Kir6.1 channel activity leading to action potential shortening, reduced Ca2+ accumulation, and preserved contractile function; inherent cardioprotection in female cardiomyocytes correlates with increased Kir6.1 activity. |
Patch-clamp recordings in isolated cardiomyocytes, adenosine and KATP modulator treatment, metabolic inhibition/washout, whole-heart coronary ligation, Ca2+ measurements |
Frontiers in physiology |
Medium |
42088949
|