A novel cytidine deaminase AIDs in the delivery of error-prone polymerases to immunoglobulin genes

Abstract

Immunoglobulin genes undergo somatic hypermutation in activated B lymphocytes. The mutations are targeted to the variable region of the gene, apparently by co-transcriptional deposition of a mutation complex. The novel activation induced deaminase (AID) gene is required for this process and recent work indicates that it is the cytidine deaminase activity of the AID protein rather than an associated RNA editing function that is required [Curr. Biol. 12 (2002) 1748; Nature 419 (2002) 1; Nature 418 (2002) 99]. The authors review the implications of this work and argue that deamination of deoxy-cytidine to deoxy-uracil seems to initiate several pathways in which error-prone polymerases are postulated to create mutations.