Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
2009-10-5
pubmed:abstractText
The oxidized DNA base 8-oxoguanine (8-oxoG) is implicated in neuronal CAG repeat expansion associated with Huntington disease, yet it is unclear how such a DNA base lesion and its repair might cause the expansion. Here, we discovered size-limited expansion of CAG repeats during repair of 8-oxoG in a wild-type mouse cell extract. This expansion was deficient in extracts from cells lacking pol beta and HMGB1. We demonstrate that expansion is mediated through pol beta multinucleotide gap-filling DNA synthesis during long-patch base excision repair. Unexpectedly, FEN1 promotes expansion by facilitating ligation of hairpins formed by strand slippage. This alternate role of FEN1 and the polymerase beta (pol beta) multinucleotide gap-filling synthesis is the result of uncoupling of the usual coordination between pol beta and FEN1. HMGB1 probably promotes expansion by stimulating APE1 and FEN1 in forming single strand breaks and ligatable nicks, respectively. This is the first report illustrating that disruption of pol beta and FEN1 coordination during long-patch BER results in CAG repeat expansion.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
9
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
28352-66
pubmed:dateRevised
2010-10-12
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Coordination between polymerase beta and FEN1 can modulate CAG repeat expansion.
pubmed:affiliation
Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural