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 subset of potassium channels. To date, seven subfamilies have been identified in various mammalian cell types, plants, and bacteria. They are activated by phosphatidylinos ...
.
The
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
encoding the channel is called
KCNJ11
Kir6.2 is a major subunit of the ATP-sensitive K+ channel, a lipid-gated inward-rectifier potassium ion channel. The gene encoding the channel is called KCNJ11 and mutations in this gene are associated with congenital hyperinsulinism.
Structu ...
and mutations in this gene are associated with
congenital hyperinsulinism
Congenital hyperinsulinism is a medical term referring to a variety of congenital disorders in which hypoglycemia is caused by excessive insulin secretion.update 2013 Congenital forms of hyperinsulinemic hypoglycemia can be transient or persiste ...
.
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 act ...
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 familial
persistent hyperinsulinemic hypoglycemia of infancy
Congenital hyperinsulinism is a medical term referring to a variety of congenital disorders in which hypoglycemia is caused by excessive insulin secretion.update 2013 Congenital forms of hyperinsulinemic hypoglycemia can be transient or persiste ...
(PHHI), 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 effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
non-insulin-dependent diabetes mellitus type II
Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by hyperglycemia, high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include polydipsia, increased th ...
(NIDDM).
See also
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Inward-rectifier potassium ion channel
Inward-rectifier potassium channels (Kir, IRK) are a specific lipid-gated subset of potassium channels. To date, seven subfamilies have been identified in various mammalian cell types, plants, and bacteria. They are activated by phosphatidylinos ...
*
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 cel ...
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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