A minimal threshold of FANCJ helicase activity is required for its response to replication stress or double-strand break repair.
A minimal threshold of FANCJ helicase activity is required for its response to replication stress or double-strand break repair.
复制标题
DOI：
10.1093/nar/gky403
复制
发表时间：
2018-07-06
影响因子：
14.9
通讯作者：
Brosh RM Jr
中科院分区：
文献类型：
--
作者：
Bharti SK;Sommers JA;Awate S;Bellani MA;Khan I;Bradley L;King GA;Seol Y;Vidhyasagar V;Wu Y;Abe T;Kobayashi K;Shin-Ya K;Kitao H;Wold MS;Branzei D;Neuman KC;Brosh RM Jr
范可尼贫血（Fanconi Anemia， FA）以骨髓衰竭、先天性异常和癌症为特征。在20多个fa相关基因中，FANCJ独特地编码DNA解旋酶，其突变也与乳腺癌和卵巢癌相关。fancj - / -细胞对DNA链交联（ICL）和复制叉延迟药物敏感。我们描述了两个FA患者衍生的FANCJ解旋酶结构域突变的分子缺陷。FANCJ-R707C在二聚化和解旋酶能力上受到损害，而FANCJ-H396D的DNA解绕几乎没有检测到。FANCJ-R707C和FANCJ-H396D的DNA结合和ATP水解均存在缺陷，后者的还原程度更大。fancj - r707c或fancj - h396d在fancj−/−细胞中的表达未能挽救顺铂或丝裂霉素的敏感性。活细胞成像显示FANCJ-R707C对激光诱导的DNA损伤的招募明显受损。然而，在fancj-/-细胞中表达的fancj- r707c对DNA聚合酶抑制剂aphidicolin、g -四重配体端粒抑素或DNA链断裂者博来霉素具有耐药性，而fancj- h396d则没有。因此，FANCJ催化活性的最小阈值需要克服阿菲霉素或端米司汀诱导的复制应激，或修复博莱霉素诱导的DNA断裂。这些发现对依赖于DNA交联敏感性或癌细胞特征的高复制应激的治疗策略具有启示意义。
Fanconi Anemia (FA) is characterized by bone marrow failure, congenital abnormalities, and cancer. Of over 20 FA-linked genes, FANCJ uniquely encodes a DNA helicase and mutations are also associated with breast and ovarian cancer. fancj−/− cells are sensitive to DNA interstrand cross-linking (ICL) and replication fork stalling drugs. We delineated the molecular defects of two FA patient-derived FANCJ helicase domain mutations. FANCJ-R707C was compromised in dimerization and helicase processivity, whereas DNA unwinding by FANCJ-H396D was barely detectable. DNA binding and ATP hydrolysis was defective for both FANCJ-R707C and FANCJ-H396D, the latter showing greater reduction. Expression of FANCJ-R707C or FANCJ-H396D in fancj−/− cells failed to rescue cisplatin or mitomycin sensitivity. Live-cell imaging demonstrated a significantly compromised recruitment of FANCJ-R707C to laser-induced DNA damage. However, FANCJ-R707C expressed in fancj-/- cells conferred resistance to the DNA polymerase inhibitor aphidicolin, G-quadruplex ligand telomestatin, or DNA strand-breaker bleomycin, whereas FANCJ-H396D failed. Thus, a minimal threshold of FANCJ catalytic activity is required to overcome replication stress induced by aphidicolin or telomestatin, or to repair bleomycin-induced DNA breakage. These findings have implications for therapeutic strategies relying on DNA cross-link sensitivity or heightened replication stress characteristic of cancer cells.
登录
查看更多内容
影响因子：
16
作者：
Gong, Zihua;Kim, Ja-Eun;Leung, Charles Chung Yun;Glover, J. N. Mark;Chen, Junjie
通讯作者：
Chen, Junjie
影响因子：
14.8
作者：
Kelley LA;Mezulis S;Yates CM;Wass MN;Sternberg MJ
通讯作者：
Sternberg MJ
影响因子：
3.7
作者：
Brosh RM Jr;Cantor SB
通讯作者：
Cantor SB
影响因子：
16.8
作者：
Davies, Sally L.;North, Phillip S.;Hickson, Ian D.
通讯作者：
Hickson, Ian D.
影响因子：
4.8
作者：
Guo, Manhong;Vidhyasagar, Venkatasubramanian;Wu, Yuliang
通讯作者：
Wu, Yuliang