Double-stranded DNA break polarity skews repair pathway choice during intrachromosomal and interchromosomal recombination.
Proc Natl Acad Sci U S A
; 115(11): 2800-2805, 2018 03 13.
Article
em En
| MEDLINE
| ID: mdl-29472448
ABSTRACT
Activation-induced cytidine deaminase (AID) inflicts DNA damage at Ig genes to initiate class switch recombination (CSR) and chromosomal translocations. However, the DNA lesions formed during these processes retain an element of randomness, and thus knowledge of the relationship between specific DNA lesions and AID-mediated processes remains incomplete. To identify necessary and sufficient DNA lesions in CSR, the Cas9 endonuclease and nickase variants were used to program DNA lesions at a greater degree of predictability than is achievable with conventional induction of CSR. Here we show that Cas9-mediated nicks separated by up to 250 nucleotides on opposite strands can mediate CSR. Staggered double-stranded breaks (DSBs) result in more end resection and junctional microhomology than blunt DSBs. Moreover, Myc-Igh chromosomal translocations, which are carried out primarily by alternative end joining (A-EJ), were preferentially induced by 5' DSBs. These data indicate that DSBs with 5' overhangs skew intrachromosomal and interchromosomal end-joining toward A-EJ. In addition to lending potential insight to AID-mediated phenomena, this work has broader carryover implications in DNA repair and lymphomagenesis.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Recombinação Genética
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Cromossomos de Mamíferos
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Quebras de DNA de Cadeia Dupla
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Reparo do DNA por Junção de Extremidades
Limite:
Animals
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article