Nudix hydrolase 15 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the NUDT15
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
The NUDT15 gene encodes an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that belongs to the
Nudix hydrolase superfamily. Members of this superfamily catalyze the hydrolysis of
nucleoside diphosphates, including
substrate
Substrate may refer to:
Physical layers
*Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached
** Substrate (aquatic environment), the earthy material that exi ...
s like
8-oxo-dGTP, which are a result of
oxidative damage
Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. Disturbances in the normal r ...
, and can induce
base mispairing during
DNA replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all life, living organisms, acting as the most essential part of heredity, biolog ...
, causing
transversion
Transversion, in molecular biology, refers to a point mutation in DNA in which a single (two ring) purine ( A or G) is changed for a (one ring) pyrimidine ( T or C), or vice versa. A transversion can be spontaneous, or it can be caused by ioniz ...
s. The encoded enzyme is a negative regulator of
thiopurine
The thiopurine drugs are purine antimetabolites widely used in the treatment of acute lymphoblastic leukemia, autoimmune disorders (e.g., Crohn's disease, rheumatoid arthritis), and organ transplant recipients.
Metabolism is catalyzed by S-met ...
activation and toxicity. Mutations in this gene result in poor metabolism of thiopurines, and are associated with thiopurine-induced early
leukopenia
Leukopenia () is a decrease in the number of white blood cells (leukocytes). It places individuals at increased risk of infection as white blood cells are the body's primary defense against infections.
Signs and symptoms
Symptoms may include:
* s ...
. Multiple
pseudogene
Pseudogenes are nonfunctional segments of DNA that resemble functional genes. Pseudogenes can be formed from both protein-coding genes and non-coding genes. In the case of protein-coding genes, most pseudogenes arise as superfluous copies of fun ...
s of this gene have been identified.
NUDT15 germline variants (e.g., a missense SNP:rs116855232, inducing R139C) have been linked to clinical usage of thiopurines (e.g.,
mercaptopurine
Mercaptopurine (6-MP), sold under the brand name Purinethol among others, is a medication used for cancer and autoimmune diseases. Specifically it is used to treat acute lymphocytic leukemia (ALL), acute promyelocytic leukemia (APL), Crohn's d ...
) in
acute lymphoblastic leukemia
Acute lymphoblastic leukemia (ALL) is a cancer of the Lymphocyte, lymphoid line of blood cells characterized by the development of large numbers of lymphoblast, immature lymphocytes. Symptoms may include feeling tired, pale skin color, fever, ...
as well as inflammatory bowel diseases to avoid thiopurine-induced leukopenia. These variants also exhibit ethnicity-specific (e.g., variant allele of rs116855232 is high is East Asians and Hispanics but low in Caucasians and Africans). Rare functional variants in this gene have also been identified as being related to thiopurine-induced
myelotoxicity
Bone marrow suppression also known as myelotoxicity or myelosuppression, is the decrease in production of cells responsible for providing immunity (leukocytes), carrying oxygen (erythrocytes), and/or those responsible for normal blood clotting ( ...
,
suggesting the whole gene screening should be taken to determine the initial dosage using of thiopurine.
References
Further reading
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External links
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Nudix hydrolases
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