Structural highlights
Disease
[ABCC8_HUMAN] Diazoxide-resistant focal hyperinsulinism due to SUR1 deficiency;Autosomal dominant hyperinsulinism due to SUR1 deficiency;Transient neonatal diabetes mellitus;DEND syndrome;Autosomal recessive hyperinsulinism due to SUR1 deficiency;MODY;Permanent neonatal diabetes mellitus. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry.
Function
[ABCC8_HUMAN] Subunit of the beta-cell ATP-sensitive potassium channel (KATP). Regulator of ATP-sensitive K(+) channels and insulin release.[1] [2]
Publication Abstract from PubMed
KATP channels are metabolic sensors that translate intracellular ATP/ADP balance into membrane excitability. The molecular composition of KATP includes an inward-rectifier potassium channel (Kir) and an ABC transporter-like sulfonylurea receptor (SUR). Although structures of KATP have been determined in many conformations, in all cases, the pore in Kir is closed. Here, we describe human pancreatic KATP (hKATP) structures with an open pore at 3.1- to 4.0-A resolution using single-particle cryo-electron microscopy (cryo-EM). Pore opening is associated with coordinated structural changes within the ATP-binding site and the channel gate in Kir. Conformational changes in SUR are also observed, resulting in an area reduction of contact surfaces between SUR and Kir. We also observe that pancreatic hKATP exhibits the unique (among inward-rectifier channels) property of PIP2-independent opening, which appears to be correlated with a docked cytoplasmic domain in the absence of PIP2.
Molecular structure of an open human KATP channel.,Zhao C, MacKinnon R Proc Natl Acad Sci U S A. 2021 Nov 30;118(48). pii: 2112267118. doi:, 10.1073/pnas.2112267118. PMID:34815345[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Saint-Martin C, Zhou Q, Martin GM, Vaury C, Leroy G, Arnoux JB, de Lonlay P, Shyng SL, Bellanne-Chantelot C. Monoallelic ABCC8 mutations are a common cause of diazoxide-unresponsive diffuse form of congenital hyperinsulinism. Clin Genet. 2015 May;87(5):448-54. doi: 10.1111/cge.12428. Epub 2014 Jun 6. PMID:24814349 doi:http://dx.doi.org/10.1111/cge.12428
- ↑ Harel S, Cohen AS, Hussain K, Flanagan SE, Schlade-Bartusiak K, Patel M, Courtade J, Li JB, Van Karnebeek C, Kurata H, Ellard S, Chanoine JP, Gibson WT. Alternating hypoglycemia and hyperglycemia in a toddler with a homozygous p.R1419H ABCC8 mutation: an unusual clinical picture. J Pediatr Endocrinol Metab. 2015 Mar;28(3-4):345-51. doi: 10.1515/jpem-2014-0265. PMID:25720052 doi:http://dx.doi.org/10.1515/jpem-2014-0265
- ↑ Zhao C, MacKinnon R. Molecular structure of an open human KATP channel. Proc Natl Acad Sci U S A. 2021 Nov 30;118(48). pii: 2112267118. doi:, 10.1073/pnas.2112267118. PMID:34815345 doi:http://dx.doi.org/10.1073/pnas.2112267118
