Structure of an open KATP channel reveals tandem PIP2 binding sites mediating the Kir6.2 and SUR1 regulatory interface

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Март 20, 2024

Abstract ATP-sensitive potassium (K ATP ) channels, composed of four pore-lining Kir6.2 subunits and regulatory sulfonylurea receptor 1 (SUR1) subunits, control insulin secretion in pancreatic β-cells. K channel opening is stimulated by PIP 2 inhibited ATP. Mutations that increase reduce inhibition cause neonatal diabetes. Although considerable evidence has implicated a role for function, previously solved open-channel structures have lacked bound , mechanisms which regulates channels remain unresolved. Here, we report the cryoEM structure harboring diabetes mutation Kir6.2-Q52R, open conformation, to amphipathic molecules consistent with natural C18:0/C20:4 long-chain PI(4,5)P at two adjacent binding sites between SUR1 Kir6.2. The canonical site conserved among -gated Kir channels. non-canonical forms interface SUR1. Functional studies demonstrate both determine activity. pore associated twist cytoplasmic domain rotation N-terminal transmembrane SUR1, widens inhibitory pocket disfavor binding. conformation particularly stabilized Kir6.2-Q52R residue through cation-π bonding SUR1-W51. Together, these results uncover cooperation gating, explain antagonistic regulation ATP, provide putative mechanism stabilizes an

Язык: Английский

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Dynamic duo: Kir6 and SUR in K _ATP channel structure and function

Channels, Год журнала: 2024, Номер 18(1)

Опубликована: Март 15, 2024

K

Язык: Английский

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Non-radioactive Rb+ Efflux Assay for Screening KATP Channel Modulators

Methods in molecular biology, Год журнала: 2024, Номер unknown, С. 191 - 210

Опубликована: Янв. 1, 2024

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AI-Based Discovery and CryoEM Structural Elucidation of a KATP Channel Pharmacochaperone

Опубликована: Март 11, 2025

Pancreatic K ATP channel trafficking defects underlie congenital hyperinsulinism (CHI) cases unresponsive to the opener diazoxide, mainstay medical therapy for CHI. Current clinically used inhibitors have been shown act as pharmacochaperones and restore surface expression of mutants; however, their therapeutic utility impaired CHI is hindered by high-affinity binding, which limits functional recovery rescued channels. Recent structural studies channels employing cryo-electron microscopy (cryoEM) revealed a promiscuous pocket where several known bind. The knowledge provides framework discovering with desired reversible inhibitory effects permit Using an AI-based virtual screening technology AtomNet® followed validation, we identified novel compound, termed Aekatperone, exhibits chaperoning on mutations. Aekatperone reversibly inhibits activity half-maximal concentration (IC 50 ) ∼ 9 μM. Mutant cell showed upon washout compound. CryoEM structure bound distinct binding features compared high affinity inhibitor pharmacochaperones. Our findings unveil pharmacochaperone enabling promising caused defects.

Язык: Английский

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AI-based discovery and cryoEM structural elucidation of a KATP channel pharmacochaperone

eLife, Год журнала: 2025, Номер 13

Опубликована: Март 26, 2025

Pancreatic K ATP channel trafficking defects underlie congenital hyperinsulinism (CHI) cases unresponsive to the opener diazoxide, mainstay medical therapy for CHI. Current clinically used inhibitors have been shown act as pharmacochaperones and restore surface expression of mutants; however, their therapeutic utility trafficking-impaired CHI is hindered by high affinity binding, which limits functional recovery rescued channels. Recent structural studies channels employing cryo-electron microscopy (cryoEM) revealed a promiscuous pocket where several known bind. The knowledge provides framework discovering with desired reversible inhibitory effects permit Using an AI-based virtual screening technology AtomNet followed validation, we identified novel compound, termed Aekatperone, exhibits chaperoning on mutations. Aekatperone reversibly inhibits activity half-maximal concentration (IC 50 ) ~9 μM. Mutant cell showed upon washout compound. CryoEM structure bound distinct binding features compared inhibitor pharmacochaperones. Our findings unveil pharmacochaperone enabling promising caused defects.

Язык: Английский

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Congenital Hyperinsulinism Caused by Mutations in ABCC8 Gene Associated with Early-Onset Neonatal Hypoglycemia: Genetic Heterogeneity Correlated with Phenotypic Variability

International Journal of Molecular Sciences, Год журнала: 2024, Номер 25(10), С. 5533 - 5533

Опубликована: Май 19, 2024

Congenital hyperinsulinism (CHI) is a rare disorder of glucose metabolism and the most common cause severe persistent hypoglycemia (hyperinsulinemic hypoglycemia, HH) in neonatal period childhood. Most cases are caused by mutations ABCC8 KCNJ11 genes that encode ATP-sensitive potassium channel (KATP). We present correlation between genetic heterogeneity variable phenotype patients with early-onset HH gene mutations. In first patient, who presented since day life, molecular testing revealed presence homozygous mutation [deletion c.(2390+1_2391-1)_(3329+1_3330-1)del] correlated diffuse form (the parents being healthy heterozygous carriers). second onset was on third life identified c.1792C>T (p.Arg598*) inherited paternal line, which led to diagnosis focal hyperinsulinism. To locate lesions, (18)F-DOPA (3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine) positron emission tomography/computed tomography (PET/CT) recommended (an investigation cannot be carried out country), but refused carry abroad. this case, early surgical treatment could have been curative. addition, child also secondary adrenal insufficiency requiring replacement therapy. At same time, she developed recurrent seizures required antiepileptic treatment. emphasize importance for diagnosis, management counseling HH.

Язык: Английский

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Structure of an open K_ATPchannel reveals tandem PIP₂binding sites mediating the Kir6.2 and SUR1 regulatory interface

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Авг. 1, 2023

ATP-sensitive potassium (K

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Case report: Exceptional transmission of congenital hyperinsulinism from a focal CHI mother to her diffuse CHI dichorionic diamniotic twins

Frontiers in Endocrinology, Год журнала: 2024, Номер 15

Опубликована: Июнь 17, 2024

We present the case of a 36-year-old female who was diagnosed at birth with CHI that caused severe hypoglycaemia unresponsive to Diazoxide. Subtotal pancreatectomy performed age three weeks. Later, histological analysis her pancreas in research setting revealed focal form CHI. Genetic testing not available time. The patient developed pancreatic exocrine deficiency and insulin-dependent diabetes 9 years. In 2016, genetic test missense heterozygous variant ABCC8 gene inherited from father classified as having recessive inheritance. geneticist concluded risk for offspring would be low (1/600), making pregnancy favourable. As there no consanguinity family, future deemed unnecessary (carrier frequency 1/150 general population). occurred spontaneously 2020 gestational 28 weeks, mother went into premature labour. An emergency C-section April 2021 resulting bichorial bi-amniotic male twins. Following birth, both newborns experienced persistent which required glucagon treatment intravenous glucose infusion initially, followed by Diazoxide day 51 after without satisfactory response. Continuous Octreotide introduced on 72. Due recurrence episodes despite reaching maximum doses Octreotide, 92 switched Pasireotide. tests same genotypes infants: exon 39 (c.4716C>A; p.Ser1572Arg) their truncating (c.3550del; p.Val1184*), asymptomatic father. result inheriting two variants gene, children were diffuse CHI, consistent diazoxide-unresponsive presentation. This situation is very rare outside consanguinity. emphasises significance counselling individuals history diseases context consanguinity, potential recurrence. Prenatal diagnosis can lead better outcomes affected neonates, well help families make informed decisions about pregnancies.

Язык: Английский

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Insulin Dynamics and Pathophysiology in Youth-Onset Type 2 Diabetes

The Journal of Clinical Endocrinology & Metabolism, Год журнала: 2024, Номер 109(10), С. 2411 - 2421

Опубликована: Июль 3, 2024

Abstract Youth-onset type 2 diabetes (T2D) is increasing around the globe. The mounting disease burden of youth-onset T2D portends substantial consequences for health outcomes young people and care systems. pathophysiology this condition characterized by insulin resistance initial hypersecretion ± an inherent secretory defect, with progressive loss stimulated secretion leading to pancreatic β-cell failure. Research studies focusing on have illuminated key differences youth- vs adult-onset T2D, youth having more profound quicker progression sufficient maintain euglycemia. There a need therapies that are targeted improve both and, importantly, function over lifespan in T2D.

Язык: Английский

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AI-Based Discovery and CryoEM Structural Elucidation of a K_ATPChannel Pharmacochaperone

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Сен. 5, 2024

Pancreatic KATP channel trafficking defects underlie congenital hyperinsulinism (CHI) cases unresponsive to the opener diazoxide, mainstay medical therapy for CHI. Current clinically used inhibitors have been shown act as pharmacochaperones and restore surface expression of mutants; however, their therapeutic utility impaired CHI is hindered by high-affinity binding, which limits functional recovery rescued channels. Recent structural studies channels employing cryo-electron microscopy (cryoEM) revealed a promiscuous pocket where several known bind. The knowledge provides framework discovering with desired reversible inhibitory effects permit Using an AI-based virtual screening technology AtomNet® followed validation, we identified novel compound, termed Aekatperone, exhibits chaperoning on mutations. Aekatperone reversibly inhibits activity half-maximal concentration (IC50) ~ 9 μM. Mutant cell showed upon washout compound. CryoEM structure bound distinct binding features compared high affinity inhibitor pharmacochaperones. Our findings unveil pharmacochaperone enabling promising caused defects.

Язык: Английский

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