Pantothenate kinase 2, mitochondrial is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
that in humans is encoded by the ''PANK2''
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 b ...
.
This gene encodes a protein belonging to the
pantothenate kinase family and is the only member of that family to be expressed in
mitochondria. Pantothenate kinase is a key
regulatory enzyme in the
biosynthesis of
coenzyme A (CoA) in
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
and mammalian cells. It catalyzes the first
committed step
In enzymology, the committed step (also known as the ''first'' committed step) is an effectively irreversible enzymatic reaction that occurs at a branch point during the biosynthesis of some molecules.
As the name implies, after this step, the m ...
in the universal
biosynthetic pathway
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
leading to CoA and is itself subject to regulation through feedback inhibition by
acyl CoA
Acyl-CoA is a group of coenzymes that metabolize fatty acids. Acyl-CoA's are susceptible to beta oxidation, forming, ultimately, acetyl-CoA. The acetyl-CoA enters the citric acid cycle, eventually forming several equivalents of ATP. In this wa ...
species. Mutations in this gene are associated with HARP syndrome and
Pantothenate kinase-associated neurodegeneration
Pantothenate kinase-associated neurodegeneration (PKAN), formerly called Hallervorden–Spatz syndrome, is a genetic degenerative disease of the brain that can lead to parkinsonism, dystonia, dementia, and ultimately death. Neurodegeneration in P ...
(PKAN). Alternative splicing, involving the use of alternate first
exons, results in multiple transcripts encoding different
isoform
A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some iso ...
s.
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Pantothenate Kinase-Associated Neurodegeneration
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