Fanconi Anemia Pathway

我们最近的工作集中在FANCJ解旋酶在DNA损伤反应中的作用。 BRCA 1相关解旋酶BACH 1的突变与早发性乳腺癌相关，细胞数据表明解旋酶在双链断裂修复和检查点控制中的作用。 最近，BACH1（FANCJ）已被遗传链接到染色体不稳定性疾病范可尼贫血（FA）。 为了了解FANCJ解旋酶作用的分子功能和生物底物，我们系统地评估了纯化的重组FANCJ解旋一组具有不同尾部变异的相关DNA底物的能力，所述尾部变异包括单链与双链特征、尾部长度或骨架连续性。此外，我们还评估了BACH 1催化解链DNA结构的能力，这些DNA结构被认为是细胞DNA代谢的关键中间体。这些解旋研究的结果提供了一个平台，以调查的FANCJ解旋酶与其蛋白质的合作伙伴在双链断裂修复同源重组的分子相互作用。 在蛋白质相互作用方面，我们已经确定并表征了两个新的FANCJ伙伴，错配修复蛋白复合物MutL α和单链DNA结合蛋白RPA。 FANCJ与这些DNA修复因子的相互作用在DNA损伤反应中起重要作用。 我们目前的努力是为了了解FANCJ在经典的FA通路的交联修复以及稳定和复制叉的进展中的作用。

Our recent work has focused on the roles of the FANCJ helicase in the DNA damage response. Mutations in the BRCA1-associated helicase BACH1 have been associated with early-onset breast cancer and cellular data suggest a role of the helicase in double strand break repair and checkpoint control. Recently, BACH1 (FANCJ) has been genetically linked to the chromosomal instability disorder Fanconi anemia (FA). To understand the molecular functions and biological substrates that FANCJ helicase acts upon, we have systematically evaluated the ability of purified recombinant FANCJ to unwind a panel of related DNA substrates with distinct tail variations including single-stranded versus double-stranded character, tail length, or backbone continuity. In addition, we have assessed the ability of BACH1 to catalytically unwind DNA structures proposed to be key intermediates of cellular DNA metabolism. The results from these unwinding studies provide a platform to investigate the molecular interactions of the FANCJ helicase with its protein partners in double strand break repair by homologous recombination. In terms of protein interactions, we have identified and characterized two novel FANCJ partners, the mismatch repair protein complex MutL alpha and the single-stranded DNA binding protein RPA. FANCJ interactions with these DNA repair factors play important roles in the DNA damage response. Our current efforts are directed toward understanding the roles of FANCJ in the classic FA pathway of cross-link repair as well as stabilization and progression of the replication fork.