Activation-induced cytidine deaminase shuttles between nucleus and cytoplasm like apolipoprotein B mRNA editing catalytic polypeptide 1.
Activation-induced cytidine deaminase (AID) is a molecule central to initiating class switch recombination, somatic hypermutation, and gene conversion of Ig genes. However, its mechanism to initiate these genetic alterations is still unclear. AID can convert cytosine to uracil on either mRNA or DNA and is involved in DNA cleavage. Although these events are expected to take place in the nucleus, overexpressed AID was found predominantly in the cytoplasm. Here, we demonstrated that AID is a nucleocytoplasmic shuttling protein with a bipartite nuclear localization signal and a nuclear export signal in its N and C termini, respectively. In addition to previously identified genetic, structural, and biochemical similarities of AID with apolipoprotein B mRNA editing catalytic polypeptide 1, an RNA editing enzyme of ApoB100 mRNA, the present finding provides another aspect to their resemblance, suggesting that both may have homologous reaction mechanisms.
Ito
Satomi
S
Department of Medical Chemistry, Graduate School of Medicine, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
Nagaoka
Hitoshi
H
Shinkura
Reiko
R
Begum
Nasim
N
Muramatsu
Masamichi
M
Nakata
Mikiyo
M
Honjo
Tasuku
T
D000071479:APOBEC-1 Deaminase; D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D003564:Cytidine Deaminase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D041681:NIH 3T3 Cells; D019913:Nuclear Localization Signals; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
D019913:Nuclear Localization Signals; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D000071479:APOBEC-1 Deaminase; C000605089:APOBEC1 protein, human; C000605090:Apobec1 protein, mouse; D003564:Cytidine Deaminase