Bifunctional coenzyme A synthase 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. A ...
that in mammals is encoded by the ''COASY''
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 ...
that catalyses the synthesis of
coenzyme A
Coenzyme A (CoA, SHCoA, CoASH) is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle. All genomes sequenced to date encode enzymes that use coenzyme A as a subs ...
from 4'-
phosphopantetheine
Phosphopantetheine, also known as 4'-phosphopantetheine, is a prosthetic group of several acyl carrier proteins including the acyl carrier proteins (ACP) of fatty acid synthases, ACPs of polyketide synthases, the peptidyl carrier proteins (PCP), ...
.
Function
COASY is an enzyme that catalyzes the last two steps in the synthesis of
coenzyme A
Coenzyme A (CoA, SHCoA, CoASH) is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle. All genomes sequenced to date encode enzymes that use coenzyme A as a subs ...
from vitamin B
5 (
pantothenic acid
Pantothenic acid, also called vitamin B5 is a water-soluble B vitamin and therefore an essential nutrient. All animals require pantothenic acid in order to synthesize coenzyme A (CoA) – essential for fatty acid metabolism – as well as to, i ...
). The primary substrate is 4'-
phosphopantetheine
Phosphopantetheine, also known as 4'-phosphopantetheine, is a prosthetic group of several acyl carrier proteins including the acyl carrier proteins (ACP) of fatty acid synthases, ACPs of polyketide synthases, the peptidyl carrier proteins (PCP), ...
and COASY is a bifunctional enzyme in this pathway:
* 4′-Phosphopantetheine is adenylated to form dephospho-CoA by the enzyme
phosphopantetheine adenylyl-transferase (PPAT; CoaD)
* Next, dephospho-CoA is phosphorylated to coenzyme A by the enzyme
dephospho-CoA kinase
In enzymology, a dephospho-CoA kinase () is an enzyme that catalysis, catalyzes the chemical reaction
:ATP + dephospho-CoA \rightleftharpoons ADP + CoA
Thus, the two substrate (biochemistry), substrates of this enzyme are adenosine triphosphate, ...
(DPCK; CoaE)
In mammals this is a single enzyme, but in organisms including yeast and bacteria these enzymes are encoded by separate genes.
Interactions
COASY has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with
P70-S6 Kinase 1
Ribosomal protein S6 kinase beta-1 (S6K1), also known as p70S6 kinase (p70S6K, p70-S6K), is an enzyme (specifically, a protein kinase) that in humans is encoded by the ''RPS6KB1'' gene. It is a serine/threonine kinase that acts downstream of PIP3 ...
.
In 2009, COASY has also been implicated in
PI3K signaling, as it was shown to interact with a regulatory subunit of PI3K.
Clinical significance
Loss of function mutations to ''COASY'' have been associated with an ultra-rare disease that causes
neurodegeneration with brain iron accumulation
Neurodegeneration with brain iron accumulation is a heterogenous group of inherited neurodegenerative diseases, still under research, in which iron accumulates in the basal ganglia, either resulting in progressive dystonia, Parkinsonism, spastici ...
called
COASY protein-associated neurodegeneration (CoPAN), or NBIA6.
References
External links
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Further reading
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