Abstract
The error-free repair of double-stranded DNA breaks by homologous recombination requires processing of broken ends. These processed ends are substrates for assembly of DNA strand exchange proteins that mediate DNA strand invasion. Here, we establish that human BLM helicase, a member of the RecQ family, stimulates the nucleolytic activity of human exonuclease 1 (hExo1), a 5′→3′ double-stranded DNA exonuclease. The stimulation is specific because other RecQ homologs fail to stimulate hExo1. Stimulation of DNA resection by hExo1 is independent of BLM helicase activity and is, instead, mediated by an interaction between the 2 proteins. Finally, we show that DNA ends resected by hExo1 and BLM are used by human Rad51, but not its yeast or bacterial counterparts, to promote homologous DNA pairing. This in vitro system recapitulates initial steps of homologous recombination and provides biochemical evidence for a role of BLM and Exo1 in the initiation of recombinational DNA repair.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 16906-16911 |
| Number of pages | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 105 |
| Issue number | 44 |
| DOIs | |
| State | Published - Nov 4 2008 |
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Keywords
- Bloom syndrome
- DNA pairing
- Rad51
- Recombination
- RecQ
ASJC Scopus subject areas
- General
Cite this
Human exonuclease 1 and BLM helicase interact to resect DNA and initiate DNA repair. / Nimonkar, Amitabh V.; Özsoy, A. Zeynep; Genschel, Jochen; Modrich, Paul; Kowalczykowski, Stephen C.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 105, No. 44, 04.11.2008, p. 16906-16911.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Human exonuclease 1 and BLM helicase interact to resect DNA and initiate DNA repair
AU - Nimonkar, Amitabh V.
AU - Özsoy, A. Zeynep
AU - Genschel, Jochen
AU - Modrich, Paul
AU - Kowalczykowski, Stephen C.
PY - 2008/11/4
Y1 - 2008/11/4
N2 - The error-free repair of double-stranded DNA breaks by homologous recombination requires processing of broken ends. These processed ends are substrates for assembly of DNA strand exchange proteins that mediate DNA strand invasion. Here, we establish that human BLM helicase, a member of the RecQ family, stimulates the nucleolytic activity of human exonuclease 1 (hExo1), a 5′→3′ double-stranded DNA exonuclease. The stimulation is specific because other RecQ homologs fail to stimulate hExo1. Stimulation of DNA resection by hExo1 is independent of BLM helicase activity and is, instead, mediated by an interaction between the 2 proteins. Finally, we show that DNA ends resected by hExo1 and BLM are used by human Rad51, but not its yeast or bacterial counterparts, to promote homologous DNA pairing. This in vitro system recapitulates initial steps of homologous recombination and provides biochemical evidence for a role of BLM and Exo1 in the initiation of recombinational DNA repair.
AB - The error-free repair of double-stranded DNA breaks by homologous recombination requires processing of broken ends. These processed ends are substrates for assembly of DNA strand exchange proteins that mediate DNA strand invasion. Here, we establish that human BLM helicase, a member of the RecQ family, stimulates the nucleolytic activity of human exonuclease 1 (hExo1), a 5′→3′ double-stranded DNA exonuclease. The stimulation is specific because other RecQ homologs fail to stimulate hExo1. Stimulation of DNA resection by hExo1 is independent of BLM helicase activity and is, instead, mediated by an interaction between the 2 proteins. Finally, we show that DNA ends resected by hExo1 and BLM are used by human Rad51, but not its yeast or bacterial counterparts, to promote homologous DNA pairing. This in vitro system recapitulates initial steps of homologous recombination and provides biochemical evidence for a role of BLM and Exo1 in the initiation of recombinational DNA repair.
KW - Bloom syndrome
KW - DNA pairing
KW - Rad51
KW - Recombination
KW - RecQ
UR - http://www.scopus.com/inward/record.url?scp=55949105327&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=55949105327&partnerID=8YFLogxK
U2 - 10.1073/pnas.0809380105
DO - 10.1073/pnas.0809380105
M3 - Article
C2 - 18971343
AN - SCOPUS:55949105327
VL - 105
SP - 16906
EP - 16911
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 44
ER -