Inhibition of filament formation of human Rad51 protein by a small peptide derived from the BRC-motif of the BRCA2 protein
Inhibition of filament formation of human Rad51 protein by a small peptide derived from the BRC-motif of the BRCA2 protein
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DOI：
10.1111/j.1365-2443.2008.01180.x
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发表时间：
2008-05-01
期刊：
影响因子：
2.1
通讯作者：
Takahashi, Masayuki
中科院分区：
文献类型：
--
作者：
Nomme, Julian;Takizawa, Yoshimasa;Takahashi, Masayuki
人类RAD51是重组DNA修复的关键元件，与癌细胞对化疗和放射治疗的耐药性有关。因此，这种蛋白质是抗癌治疗的潜在靶点。结晶学分析表明，BRCA2抑癌基因的BRC基序与RAD51的亚基-亚基界面相接触，从而阻止了RAD51的微丝形成。然而，生化分析表明，69个氨基酸的BRC基序多肽优先与RAD51的N-末端结合。我们的实验表明，从BRC4基序衍生的28个氨基酸的短肽与亚单位-亚单位界面结合，并在DNA存在和不存在的情况下解离其细丝，当然是通过与解离的单体结合。这种抑制对RAD51是有效和特异的：该肽甚至不与RAD51同系物相互作用，也不阻止它们与DNA相互作用。该多肽的N端和C端都不与人RAD51相互作用，这表明这两个部分都参与了相互作用，正如从晶体结构中所预期的那样。这些结果表明，基于该多肽开发人RAD51的抑制剂是可能的。
Human Rad51 is a key element of recombinational DNA repair and is related to the resistance of cancer cells to chemo- and radiotherapies. The protein is thus a potential target of anti-cancer treatment. The crystallographic analysis shows that the BRC-motif of the BRCA2 tumor suppressor is in contact with the subunit-subunit interface of Rad51 and could thus prevent filament formation of Rad51. However, biochemical analysis indicates that a BRC-motif peptide of 69 amino acids preferentially binds to the N-terminal part of Rad51. We show experimentally that a short peptide of 28 amino acids derived from the BRC4 motif binds to the subunit-subunit interface and dissociates its filament, both in the presence and absence of DNA, certainly by binding to dissociated monomers. The inhibition is efficient and specific for Rad51: the peptide does not even interact with Rad51 homologs or prevent their interaction with DNA. Neither the N-terminal nor the C-terminal half of the peptide interacts with human Rad51, indicating that both parts are involved in the interaction, as expected from the crystal structure. These results suggest the possibility of developing inhibitors of human Rad51 based on this peptide.