HMGB1 is a cofactor in mammalian base excision repair
HMGB1 is a cofactor in mammalian base excision repair
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DOI：
10.1016/j.molcel.2007.06.029
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发表时间：
2007-09-07
期刊：
影响因子：
16
通讯作者：
Wilson, Samuel H.
中科院分区：
文献类型：
--
作者：
Prasad, Rajendra;Liu, Yuan;Wilson, Samuel H.
DNA聚合酶β（Pol β）去除脱氧核糖磷酸（dRP）是碱基切除修复（BER）的关键步骤。为了鉴定BER辅因子，特别是具有dRP裂解酶活性的那些，我们使用Pol 0空细胞提取物和BER中间体作为硼氢化钠交联的诱饵。质谱鉴定出高迁移率族蛋白1（HMGB 1）与BER中间体特异性相互作用。发现纯化的HMGB 1具有弱的dRP裂解酶活性，并刺激BER底物上的AP内切酶和FEN 1活性。免疫共沉淀实验揭示了HMGB 1与已知BER酶的相互作用，并且发现GFP标记的HMGB 1在活细胞中的氧化DNA损伤位点处积累。HMGB 1（-/-）小鼠细胞对MMS的抗性略高于野生型细胞，可能是由于产生较少的链断裂BER中间体。结果表明，HMGB 1是一种BER辅因子，能够调节细胞的BER容量。
Deoxyribose phosphate (dRP) removal by DNA polymerase beta (Pol beta) is a pivotal step in base excision repair (BER). To identify BER cofactors, especially those with dRP lyase activity, we used a Pol 0 null cell extract and BER intermediate as bait for sodium borohydride crosslinking. Mass spectrometry identified the high-mobility group box 1 protein (HMGB1) as specifically interacting with the BER intermediate. Purified HMGB1 was found to have weak dRP lyase activity and to stimulate AP endonuclease and FEN1 activities on BER substrates. Coimmunoprecipitation experiments revealed interactions of HMGB1 with known BER enzymes, and GFP-tagged HMGB1 was found to accumulate at sites of oxidative DNA damage in living cells. HMGB1(-/-) mouse cells were slightly more resistant to MMS than wild-type cells, probably due to the production of fewer strand-break BER intermediates. The results suggest HMGB1 is a BER cofactor capable of modulating BER capacity in cells.