AMP deaminase 3 is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

that in humans is encoded by the ''AMPD3''

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 member of the AMP deaminase gene family. The encoded protein is a highly regulated enzyme that catalyzes the hydrolytic deamination of adenosine monophosphate to inosine monophosphate, a branch point in the adenylate catabolic pathway. This gene encodes the erythrocyte (E) isoforms, whereas other family members encode isoforms that predominate in muscle (M) and liver (L) cells. Mutations in this gene lead to the clinically asymptomatic, autosomal recessive condition erythrocyte AMP deaminase deficiency. Alternatively spliced transcript variants encoding different isoforms of this gene have been described.

Model organisms

Model organisms have been used in the study of AMPD3 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 ''Ampd3^{tm2a(KOMP)Wtsi}'' was generated as part of the

International Knockout Mouse Consortium The International Knockout Mouse Consortium (IKMC) is a scientific endeavour to produce a collection of mouse embryonic stem cell lines that together lack every gene in the genome, and then to distribute the cells to scientific researchers to cr ...

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 prop ...

to determine the effects of deletion. Twenty eight 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. Mutant animals had increased IgG1 levels, increased trabecular bone thickness, decreased B cell numbers / increased granulocyte number and unusual brain histopathology (the thickness of the stratum radiatum was reduced and the dorsal

3rd ventricle The third ventricle is one of the four connected ventricles of the ventricular system within the mammalian brain. It is a slit-like cavity formed in the diencephalon between the two thalami, in the midline between the right and left lateral ve ...

area was increased). A second mouse line, called ''Ampd3''^T689A, was generated by

ENU ENU, also known as ''N''-ethyl-''N''-nitrosourea (chemical formula C3H7N3O2), is a highly potent mutagen. For a given gene in mice, ENU can induce 1 new mutation in every 700 loci. It is also toxic at high doses. The chemical is an alkylating a ...

mutagenesis. This mouse carries a mutation which increases AMPD3 function. Mutant animals have severely reduced

erythrocyte Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

lifespan, cyclic

erythropoiesis Erythropoiesis (from Greek 'erythro' meaning "red" and 'poiesis' "to make") is the process which produces red blood cells (erythrocytes), which is the development from erythropoietic stem cell to mature red blood cell. It is stimulated by decre ...

splenomegaly Splenomegaly is an enlargement of the spleen. The spleen usually lies in the left upper quadrant (LUQ) of the human abdomen. Splenomegaly is one of the four cardinal signs of ''hypersplenism'' which include: some reduction in number of circulati ...

, and resistance to infection with ''

Plasmodium chabaudi ''Plasmodium chabaudi'' is a parasite of the genus ''Plasmodium'' subgenus ''Vinckeia''. As in all ''Plasmodium'' species, ''P. chabaudi'' has both vertebrate and insect hosts. The vertebrate hosts for this parasite are rodents. Taxonomy This ...

''.

Model organisms

References

External links

Further reading