7s61
From Proteopedia
Human KATP channel in open conformation, focused on Kir and one SUR, position 5
Structural highlights
DiseaseKCJ11_HUMAN MODY;Autosomal dominant hyperinsulinism due to Kir6.2 deficiency;Intermediate DEND syndrome;Transient neonatal diabetes mellitus;Permanent neonatal diabetes mellitus;DEND syndrome;Diazoxide-resistant focal hyperinsulinism due to Kir6.2 deficiency;Autosomal recessive hyperinsulinism due to Kir6.2 deficiency. 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. Defects in KCNJ11 may contribute to non-insulin-dependent diabetes mellitus (NIDDM), also known as diabetes mellitus type 2. The disease is caused by mutations affecting the gene represented in this entry. FunctionKCJ11_HUMAN This receptor is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium (By similarity). Subunit of ATP-sensitive potassium channels (KATP). Can form cardiac and smooth muscle-type KATP channels with ABCC9. KCNJ11 forms the channel pore while ABCC9 is required for activation and regulation.[1] [2] [3] Publication Abstract from PubMedKATP 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[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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