AICDA

Function

Single-stranded DNA-specific cytidine deaminase. Involved in somatic hypermutation (SHM), gene conversion, and class-switch recombination (CSR) in B-lymphocytes by deaminating C to U during transcription of Ig-variable (V) and Ig-switch (S) region DNA. Required for several crucial steps of B-cell terminal differentiation necessary for efficient antibody responses (PubMed:18722174, PubMed:21385873, PubMed:21518874, PubMed:27716525). May also play a role in the epigenetic regulation of gene expression by participating in DNA demethylation (PubMed:21496894).

Involvement in disease

Immunodeficiency with hyper-IgM 2

HIGM2

A rare immunodeficiency syndrome characterized by normal or elevated serum IgM levels with absence of IgG, IgA, and IgE. It results in a profound susceptibility to bacterial infections.

None

The disease is caused by variants affecting the gene represented in this entry.

Post-translational modifications

Ser-38 is the major site whereas Thr-27 is the minor site of phosphorylation. Phosphorylation regulates its class-switch recombination activity.

Probably monoubiquitinated on several residues by RNF126.

Sequence similarities

Belongs to the cytidine and deoxycytidylate deaminase family.

Tissue specificity

Strongly expressed in lymph nodes and tonsils.

Cellular localization

• Nucleus
• Cytoplasm
• Predominantly cytoplasmic (PubMed:21385873). In the presence of MCM3AP/GANP, relocalizes to the nucleus (By similarity).

Alternative names

• Single-stranded DNA cytosine deaminase
• Activation-induced cytidine deaminase
• Cytidine aminohydrolase
• AID
• AID
• AICDA

Database links

• entrezGene:57379
• omim:605257
• swissprot:Q9GZX7

Target type

Proteins

Primary research area

Epigenetics

Molecular weight

23954Da