Towards an understanding of somatic hypermutation.

摘要: How germinal center (GC) B cells diversify their rearranged immunoglobulin genes by somatic hypermutation is unknown. However, the GC-specific activation-induced cytidine deaminase has been identified as a key factor controlling two central events: and class-switch recombination of genes. This may function catalytic subunit an RNA-editing complex or, more directly, on DNA deoxy-cytidine in domain region. Deamination deoxy-cytidines both strands result staggered double-strand breaks (DSBs) that, domain, become processed member(s) newly error-prone polymerases. Direct evidence for DSBs hot-spots hypermutating provided, implicating reaction intermediates DSB-repair pathway acting specifically GC cells. These recent findings are to identification mechanism.