Characterisation of DNA-Protein Crosslink Repair, a novel DNA repair pathway for protection from accelerated ageing and cancer

DNA-蛋白质交联链(DPC)是由蛋白质与DNA的共价结合引起的未被研究的DNA损伤。DPC由各种内源性化学物质诱导，如醛或化疗药物。关于细胞如何修复DPC，从而对DPC诱导的化疗产生耐药性，人们知之甚少。然而，DPC的持久性会导致基因组不稳定和癌症。我们最近发现了一种与DPC修复途径缺陷有关的人类综合征(Ruijs-Aalfs或Spartan综合征)。斯巴达综合症是由斯巴达基因/蛋白的双等位基因和单基因突变引起的，以基因组不稳定、早衰和儿童肝癌为特征(Lessel等人。自然遗传学2014)。我们证明了斯巴达是一种DNA依赖的金属蛋白酶，它通过酶作用(通过其金属蛋白酶活性)从DNA中移除共价连接的蛋白质(Vaz等人)。分子细胞，2016)。总之，我们的结果表明，我们已经发现了一种新的和专门的DNA修复途径，即DNA-蛋白质交联蛋白降解修复途径，它可以保护人类免受癌症和加速衰老的影响(Vaz等人，TIBS，2017)。DPhil项目旨在通过使用标准的生化和细胞生物学技术，结合CRISPER/Cas9基因编辑、质谱学和超分辨率显微镜等最先进的技术来描绘这一新的DNA-蛋白质交联修复途径。

DNA-protein crosslinks (DPCs) are under-investigated DNA lesions caused by the covalent attachment of proteins to DNA. DPCs are induced by various endogenous chemicals like aldehydes or by chemotherapeutic drugs. Little is known about how cells repair DPCs and thus acquire resistance to DPC-induced chemotherapy. However, the persistence of DPCs causes genomic instability and cancer. We recently discovered a human syndrome (Ruijs-Aalfs or SPARTAN syndrome) related to the defective DPC repair pathway. SPARTAN syndrome is caused by biallelic and monogenic mutations in SPARTAN gene/protein, and is characterised by genomic instability, premature ageing and liver cancer in children (Lessel et al. Nature Genetics 2014). We demonstrated that SPARTAN is a DNA-dependent metalloprotease, which enzymatically (by its metalloprotease activity) removes covalently attached proteins from DNA (Vaz et al. Molecular Cell, 2016). Altogether, our results demonstrate that we have discovered a novel and specialised DNA repair pathway, namely DNA-protein crosslink proteolysis repair pathway that protects humans from cancer and accelerated ageing (Vaz et al., TIBS, 2017). DPhil project aims to delineate this new DNA-protein crosslink repair pathway by using standard biochemical and cell biological techniques coupled to the state of the art technologies such as Crisper/Cas9 gene editing, mass-spectrometry and super-resolutions microscopy.