AID upmutants isolated using a high-throughput screen highlight the immunity/cancer balance limiting DNA deaminase activity.
DNA deaminases underpin pathways in antibody diversification (AID) and anti-viral immunity (APOBEC3s). Here we show how a high-throughput bacterial papillation assay can be used to screen for AID mutants with increased catalytic activity. The upmutations focus on a small number of residues, some highlighting regions implicated in AID's substrate interaction. Many of the upmutations bring the sequence of AID closer to that of APOBEC3s. AID upmutants can yield increased antibody diversification, raising the possibility that modification of AID's specific activity might be used to regulate antibody diversification in vivo. However, upmutation of AID also led to an increased frequency of chromosomal translocations, suggesting that AID's specific activity may have been limited by the risk of genomic instability.
Wang
Meng
M
Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge, UK.
Yang
Zizhen
Z
Rada
Cristina
C
Neuberger
Michael S
MS
D000595:Amino Acid Sequence; D000818:Animals; D000916:Antibody Diversity; D001681:Biological Assay / Q000379:methods*; D003564:Cytidine Deaminase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007107:Immune System / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism; D009700:Nucleoside Deaminases / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D023741:Takifugu; D014178:Translocation, Genetic; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
D000098830:AICDA (Activation-Induced Cytidine Deaminase); D009700:Nucleoside Deaminases; D003564:Cytidine Deaminase