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Ubiquitin ligase ARF‐BP1/Mule modulates base excision repair
Author(s) -
Parsons Jason L,
Tait Phillip S,
Finch David,
Dianova Irina I,
Edelmann Mariola J,
Khoronenkova Svetlana V,
Kessler Benedikt M,
Sharma Ricky A,
McKenna W Gillies,
Dianov Grigory L
Publication year - 2009
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2009.243
Subject(s) - dna polymerase beta , base excision repair , biology , ubiquitin ligase , dna ligase , ubiquitin , dna repair , dna polymerase , microbiology and biotechnology , ddb1 , dna , dna ligases , dna glycosylase , dna damage , biochemistry , gene
Base excision repair (BER) is the major cellular pathway involved in removal of endogenous/spontaneous DNA lesions. Here, we study the mechanism that controls the steady‐state levels of BER enzymes in human cells. By fractionating human cell extract, we purified the E3 ubiquitin ligase Mule (ARF‐BP1/HectH9) as an enzyme that can ubiquitylate DNA polymerase β (Pol β), the major BER DNA polymerase. We identified lysines 41, 61 and 81 as the major sites of modification and show that replacement of these lysines to arginines leads to increased protein stability. We further show that the cellular levels of Pol β and its ubiquitylated derivative are modulated by Mule and ARF and siRNA knockdown of Mule leads to accumulation of Pol β and increased DNA repair. Our findings provide a novel mechanism regulating steady‐state levels of BER proteins.