Activation-induced cytidine deaminase shuttles between nucleus and cytoplasm like apolipoprotein B mRNA editing catalytic polypeptide 1

S Ito, H Nagaoka, R Shinkura… - Proceedings of the …, 2004 - National Acad Sciences
S Ito, H Nagaoka, R Shinkura, N Begum, M Muramatsu, M Nakata, T Honjo
Proceedings of the National Academy of Sciences, 2004National Acad Sciences
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 …
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.
National Acad Sciences