Dissociation of in vitro DNA deamination activity and physiological functions of AID mutants.

ABSTRACT: Activation-induced cytidine deaminase (AID) is essential for the DNA cleavage that initiates both somatic hypermutation (SHM) and class switch recombination (CSR) of the Ig gene. Two alternative mechanisms of DNA cleavage by AID have been proposed: RNA editing and DNA deamination. In support of the latter, AID has DNA deamination activity in cell-free systems that is assumed to represent its physiological function. To test this hypothesis, we generated various mouse AID mutants and compared their DNA deamination, CSR, and SHM activities. Here, we compared DNA deamination, CSR, and SHM activities of various AID mutants and found that most of their CSR or SHM activities were disproportionate with their DNA deamination activities. Specifically, we identified a cluster of mutants (H48A, L49A,

SUBMITTER: Shivarov V 

PROVIDER: S-EPMC2572969 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature