What does cytidine deaminase do?
Abstract. Cytidine deaminases with the capacity to act on nucleic acids play a critical role in regulating the proteome through diversification of expressed sequence beyond that encoded in the genome. A family of these enzymes, known as the APOBEC family of cytidine deaminases, has been identified in mammalian cells.
Why is cytosine deaminase important?
Cytosine deaminase, present in bacteria and fungi, but not in mammalian cells, catalyzes the hydrolytic deamination of the pyrimidine base cytosine (cytidine without the ribose moiety) to uracil. This product, when converted to uridine and then to uridine monophosphate, serves as a precursor for nucleic acid synthesis.
What is the substrate for cytidine deaminase?
Cytidine Deaminase Substrates
| Drug | Target | Type |
|---|---|---|
| Azacitidine | Cytidine deaminase | enzyme |
| Azacitidine | DNA | target |
| Azacitidine | RNA | target |
| Capecitabine | Thymidylate synthase | target |
What does Apobec stand for?
APOBEC stands for apolipoprotein B mRNA-editing enzyme, catalytic polypeptide. As the name suggests, this class of enzyme was originally identified as an enzyme that edits mRNA species by deaminating cytosine to uracil, which in this case produces a stop codon and truncated protein (Anant & Davidson, 2001).
What does activation-induced cytidine deaminase do?
Activation-induced cytidine deaminase, also known as AICDA, AID and single-stranded DNA cytosine deaminase, is a 24 kDa enzyme which in humans is encoded by the AICDA gene. It creates mutations in DNA by deamination of cytosine base, which turns it into uracil (which is recognized as a thymine).
What is the purpose of somatic hypermutation?
Somatic hypermutation is a process that allows B cells to mutate the genes that they use to produce antibodies. This enables the B cells to produce antibodies that are better able to bind to bacteria, viruses and other infections.
How common is activation-induced cytidine deaminase deficiency?
Immunoglobulin class switch recombination deficiencies (CSR-D) are rare primary immunodeficiencies with an estimated frequency of about 1 in 200,000 births.
What is APOBEC mutation?
One of the most prominent mutation signatures in cancer, present in over half of human tumors, is called the APOBEC signature, or Signatures 2/13, and derives from the activity of the APOBEC3A (A3A) and APOBEC3B (A3B) cytosine deaminases, which preferentially deaminate cytosines in the context of an immediately …
Where is APOBEC found?
APOBEC (apolipoprotein BmRNA-editing catalytic polypeptide) proteins are a group of cytidine deaminases, which in humans include AID and APOBEC1 (located on chromosome 12); APOBEC2 (chromosome 6); and a series of seven APOBEC3 genes, which are tandemly arrayed on human chromosome 22 [12].
What causes somatic hypermutation?
Somatic hypermutation (or SHM) is a cellular mechanism by which the immune system adapts to the new foreign elements that confront it (e.g. microbes), as seen during class switching.