5'-AMP-activated protein kinase subunit beta-1 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 ''PRKAB1''
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 ...
.
The protein encoded by this gene is a regulatory subunit of the
AMP-activated protein kinase
5' AMP-activated protein kinase or AMPK or 5' adenosine monophosphate-activated protein kinase is an enzyme (EC 2.7.11.31) that plays a role in cellular energy homeostasis, largely to activate glucose and fatty acid uptake and oxidation when cell ...
(AMPK). AMPK is a heterotrimer consisting of an alpha catalytic subunit, and non-catalytic beta and gamma subunits. AMPK is an important energy-sensing enzyme that monitors cellular energy status. In response to cellular metabolic stresses, AMPK is activated, and thus
phosphorylates
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, whi ...
and inactivates
acetyl-CoA carboxylase (ACC) and
beta-hydroxy beta-methylglutaryl-CoA reductase (HMGCR), key enzymes involved in regulating de novo biosynthesis of
fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...
and
cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...
. This subunit may be a positive regulator of AMPK activity. The
myristoylation
Myristoylation is a lipidation modification where a myristoyl group, derived from myristic acid, is covalently attached by an amide bond to the alpha-amino group of an N-terminal glycine residue. Myristic acid is a 14-carbon saturated fatty ...
and phosphorylation of this subunit have been shown to affect the enzyme activity and cellular localization of AMPK. This subunit may also serve as an adaptor molecule mediating the association of the AMPK complex.
Model organisms
Model organisms have been used in the study of PRKAB1 function. A conditional
knockout mouse
A knockout mouse, or knock-out mouse, is a genetically modified mouse (''Mus musculus'') in which researchers have inactivated, or " knocked out", an existing gene by replacing it or disrupting it with an artificial piece of DNA. They are importa ...
line, called ''Prkab1
tm1a(KOMP)Wtsi''
was generated as part of the
International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.
Male and female animals underwent a standardized
phenotypic screen
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...
to determine the effects of deletion.
Twenty five tests were carried out on
mutant
In biology, and especially in genetics, a mutant is an organism or a new genetic character arising or resulting from an instance of mutation, which is generally an alteration of the DNA sequence of the genome or chromosome of an organism. It ...
mice and four significant abnormalities were observed.
Homozygous mutant males displayed
impaired glucose tolerance
Prediabetes is a component of the metabolic syndrome and is characterized by elevated blood sugar levels that fall below the threshold to diagnose diabetes mellitus. It usually does not cause symptoms but people with prediabetes often have obesit ...
. Animals of both sex had increased circulating
bilirubin levels, increased IgG3 levels, and a number of atypical
haematology
Hematology ( always spelled haematology in British English) is the branch of medicine concerned with the study of the cause, prognosis, treatment, and prevention of diseases related to blood. It involves treating diseases that affect the produc ...
parameters.
Interactions
PRKAB1 has been shown to
interact with
PRKAG2
5'-AMP-activated protein kinase subunit gamma-2 is an enzyme that in humans is encoded by the ''PRKAG2'' gene.
Function
AMP-activated protein kinase (AMPK) is a heterotrimeric protein composed of a catalytic alpha subunit, a noncatalytic beta s ...
and
PRKAG1
5'-AMP-activated protein kinase subunit gamma-1 is an enzyme that in humans is encoded by the ''PRKAG1'' gene.
Function
The protein encoded by this gene is a regulatory subunit of the AMP-activated protein kinase (AMPK). AMPK is a heterotrimer ...
.
[
The 5'-AMP-activated protein kinase beta subunit interaction domain (AMPKBI) is a conserved domain found in the beta subunit of the 5-AMP-activated protein kinase complex, and its ]yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constit ...
homologues Sip1 (SNF1-interacting protein 1), Sip2 (SNF1-interacting protein 2) and Gal83 (galactose metabolism 83), which are found in the SNF1 (sucrose non-fermenting) kinase complex
Complex commonly refers to:
* Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe
** Complex system, a system composed of many components which may interact with each ...
.
References
Further reading
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External links
PDBe-KB
provides an overview of all the structure information available in the PDB for Human 5'-AMP-activated protein kinase subunit beta-1 (PRKAB1)
{{InterPro content, IPR006828
Genes mutated in mice
EC 2.7.11