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Variable deletion and duplication at recombination junction ends: implication for staggered double-strand cleavage in class-switch recombination.

ABSTRACT: Immunoglobulin class-switch recombination (CSR) gives rise to looped-out circular DNA of a cleaved S segment, which is lost eventually after cell divisions. To understand the molecular mechanism of S region cleavage during CSR, we constructed artificial CSR substrates in which inversion-type CSR takes place to retain the cleaved S segment. Sequencing analyses of recombinant clones of these substrates revealed that varying degrees of deletions and duplications exist at CSR breakpoints, suggesting the involvement of staggered cleavage of the S region in CSR. In addition, mutations frequently found near junctions showed a similar profile of base replacement to Ig somatic hypermutation. These findings suggest that single-strand tails of staggered cleavage may be repaired by error-prone DNA synthesis.

SUBMITTER: Chen X

PROVIDER: S-EPMC61132 | biostudies-literature | 2001 Nov

REPOSITORIES: biostudies-literature

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Variable deletion and duplication at recombination junction ends: implication for staggered double-strand cleavage in class-switch recombination.

Chen X X Kinoshita K K Honjo T T

Proceedings of the National Academy of Sciences of the United States of America 20011101 24

Immunoglobulin class-switch recombination (CSR) gives rise to looped-out circular DNA of a cleaved S segment, which is lost eventually after cell divisions. To understand the molecular mechanism of S region cleavage during CSR, we constructed artificial CSR substrates in which inversion-type CSR takes place to retain the cleaved S segment. Sequencing analyses of recombinant clones of these substrates revealed that varying degrees of deletions and duplications exist at CSR breakpoints, suggesting ...[more]

PMID: 11717442

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