Inward rectifier potassium channel that forms the pore of ATP-sensitive potassium channels (KATP), regulating potassium permeability as a function of cytoplasmic ATP and ADP concentrations in many different cells (PubMed:29286281, PubMed:34815345). 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). In pancreatic cells, it forms KATP channels with ABCC8/SUR1 (PubMed:29286281, PubMed:34815345).

Can form cardiac and smooth muscle-type KATP channels with ABCC9

Homotetramer; the homotetramer binds four ATP molecules (one ATP per subunit) (PubMed:29286281, PubMed:34815345). Forms an heterooctamer with ABCC8/SUR1; one KCNJ11 homotetramer interacts with four ABCC8/SUR1 molecules (PubMed:34815345, PubMed:9831708). Interacts with ABCC9/SUR2

There are two PtdIns(4,5)P2 binding sites: A canonical site where the phosphate groups of one PtdIns(4,5)P2 molecule are coordinated at least by residues Lys-67, Trp-68 and Arg-176; a non-canonical site where the second PtdIns(4,5)P2 molecule is coordinated by both KCNJ11 and ABCC8/SUR1 residues

• Hyperinsulinemic hypoglycemia, familial, 2 (HHF2)

  A form of hyperinsulinemic hypoglycemia, a clinically and genetically heterogeneous disorder characterized by inappropriate insulin secretion from the pancreatic beta-cells in the presence of low blood glucose levels. HHF2 is a common cause of persistent hypoglycemia in infancy. Unless early and aggressive intervention is undertaken, brain damage from recurrent episodes of hypoglycemia may occur.

  HHF2 inheritance can be autosomal dominant or autosomal recessive.

• Diabetes mellitus, permanent neonatal, 2 (PNDM2)

  A form of permanent neonatal diabetes mellitus, a type of diabetes characterized by onset of persistent hyperglycemia within the first six months of life. Initial clinical manifestations include intrauterine growth retardation, hyperglycemia, glycosuria, osmotic polyuria, severe dehydration, and failure to thrive. Some PNDM2 patients may also have developmental delay, muscle weakness, epilepsy and dysmorphic features.

  PNDM2 transmission pattern is consistent with autosomal dominant inheritance.

• Diabetes mellitus, transient neonatal, 3 (TNDM3)

  An autosomal dominant form of diabetes mellitus defined by the onset of insulin-requiring hyperglycemia within the first month of life. In about half of the neonates, diabetes is transient and resolves at a median age of 3 months, whereas the rest have a permanent form of diabetes. TNDM3 onset is variable and onset in the third decade of life has been described in some patients.

• Unknown disease
• Maturity-onset diabetes of the young 13 (MODY13)

  A form of diabetes that is characterized by an autosomal dominant mode of inheritance, onset in childhood or early adulthood (usually before 25 years of age), a primary defect in insulin secretion and frequent insulin-independence at the beginning of the disease.