Department of Genetics, Harvard University Medical School, Boston, MA 02115, USA.
Proc Natl Acad Sci U S A. 2010 Oct 26;107(43):18475-80. doi: 10.1073/pnas.1012946107. Epub 2010 Oct 11.
Many proteins that respond to DNA damage are recruited to DNA lesions. We used a proteomics approach that coupled isotopic labeling with chromatin fractionation and mass spectrometry to uncover proteins that associate with damaged DNA, many of which are involved in DNA repair or nucleolar function. We show that polycomb group members are recruited by poly(ADP ribose) polymerase (PARP) to DNA lesions following UV laser microirradiation. Loss of polycomb components results in IR sensitivity of mammalian cells and Caenorhabditis elegans. PARP also recruits two components of the repressive nucleosome remodeling and deacetylase (NuRD) complex, chromodomain helicase DNA-binding protein 4 (CHD4) and metastasis associated 1 (MTA1), to DNA lesions. PARP plays a role in removing nascent RNA and elongating RNA polymerase II from sites of DNA damage. We propose that PARP sets up a transient repressive chromatin structure at sites of DNA damage to block transcription and facilitate DNA repair.
许多响应 DNA 损伤的蛋白质被招募到 DNA 损伤部位。我们使用一种蛋白质组学方法，将同位素标记与染色质分级分离和质谱相结合，以揭示与受损 DNA 结合的蛋白质，其中许多涉及 DNA 修复或核仁功能。我们表明，聚（ADP 核糖）聚合酶（PARP）在紫外线激光微照射后通过聚（ADP 核糖）将多梳组蛋白成员募集到 DNA 损伤部位。多梳组蛋白成分的缺失导致哺乳动物细胞和秀丽隐杆线虫对 IR 敏感。PARP 还招募抑制核小体重塑和去乙酰化（NuRD）复合物的两个组成部分，染色质螺旋酶 DNA 结合蛋白 4（CHD4）和转移相关蛋白 1（MTA1），到 DNA 损伤部位。PARP 在从 DNA 损伤部位去除新生 RNA 和延长 RNA 聚合酶 II 方面发挥作用。我们提出，PARP 在 DNA 损伤部位建立一个短暂的抑制性染色质结构，以阻止转录并促进 DNA 修复。
