K
ir6.2 is a major subunit of the
ATP-sensitive K+ channel, a
lipid-gated inward-rectifier potassium ion channel
Inward-rectifier potassium channels (Kir, IRK) are a specific Lipid-gated_ion_channels, lipid-gated subset of potassium channels. To date, seven subfamilies have been identified in various mammalian cell types, plants, and bacteria. They are acti ...
.
The
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
encoding the channel is called KCNJ11 and mutations in this gene are associated with
congenital hyperinsulinism Congenital hyperinsulinism (HI or CHI) is a condition causing severe Neonatal hypoglycemia, hypoglycemia (low blood sugar) in newborns due to the overproduction of insulin. There are various causes of HI, some of which are known to be the resu ...
.
Structure
It is an integral membrane protein. The protein, which has a greater tendency to allow potassium to flow into a cell rather than out of a cell, is controlled by
G-protein
G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. Their ...
s and is found associated with the
sulfonylurea receptor
In molecular biology, the sulfonylurea receptors (SUR) are membrane proteins which are the molecular targets of the sulfonylurea class of antidiabetic drugs whose mechanism of action is to promote insulin release from pancreatic beta cells. More ...
(SUR) to constitute the ATP-sensitive K
+ channel.
Pathology
Mutations in this gene are a cause of
congenital hyperinsulinism Congenital hyperinsulinism (HI or CHI) is a condition causing severe Neonatal hypoglycemia, hypoglycemia (low blood sugar) in newborns due to the overproduction of insulin. There are various causes of HI, some of which are known to be the resu ...
(CHI), an autosomal recessive disorder characterized by unregulated insulin secretion.
Defects in this gene may also contribute to
autosomal dominant
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The firs ...
non-insulin-dependent diabetes mellitus type II (NIDDM).
See also
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Inward-rectifier potassium ion channel
Inward-rectifier potassium channels (Kir, IRK) are a specific Lipid-gated_ion_channels, lipid-gated subset of potassium channels. To date, seven subfamilies have been identified in various mammalian cell types, plants, and bacteria. They are acti ...
*
Potassium channel
Potassium channels are the most widely distributed type of ion channel found in virtually all organisms. They form potassium-selective pores that span cell membranes. Potassium channels are found in most cell types and control a wide variety of ...
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Familial Hyperinsulinism GeneReviews/NCBI/NIH/UW entry on Permanent Neonatal Diabetes Mellitus*
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Ion channels
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