Indig Fred Eliezer, Partridge Juneth Joaquin, von Kobbe Cayetano, Aladjem Mirit I, Latterich Martin, Bohr Vilhelm A
Laboratory of Molecular Gerontology, NIA, NIH, Baltimore MD 21224, USA.
J Struct Biol. 2004 Apr-May;146(1-2):251-9. doi: 10.1016/j.jsb.2003.11.009.
We have previously shown that the Werner syndrome helicase, WRNp, a member of the RecQ helicase family, forms a tight molecular complex with the p97/Valosin containing protein (VCP), a member of the AAA (ATPases associated with diverse cellular activities) family of proteins. This interaction is disrupted by chemical agents that confer DNA damage, suggesting that VCP plays an important role in the signal-dependent release of WRNp from its nucleolar sequestration site. Here, we characterized the structural requirements for interactions between WRNp and VCP and for the nuclear localization of VCP. We discovered that VCP directly binds to the RQC (RecQ conserved) domain of WRNp, which is a highly conserved motif common to the RecQ helicase family. This interaction is ATP-dependent, suggesting that VCP plays a mechanistic role in releasing WRNp from the nucleolus. Immunohistochemical analysis of various VCP domains and mutated proteins expressed in vitro demonstrated that VCP may contain several hierarchical cellular localization motifs within its domain structure.
我们之前已经表明，沃纳综合征解旋酶WRNp是RecQ解旋酶家族的成员，它与含p97/缬酪肽蛋白（VCP）形成紧密的分子复合物，VCP是与多种细胞活动相关的ATP酶（AAA）家族的成员。这种相互作用被导致DNA损伤的化学试剂破坏，这表明VCP在依赖信号将WRNp从其核仁隔离位点释放中起重要作用。在这里，我们表征了WRNp与VCP之间相互作用以及VCP核定位的结构要求。我们发现VCP直接结合到WRNp的RQC（RecQ保守）结构域，这是RecQ解旋酶家族共有的高度保守基序。这种相互作用是ATP依赖性的，表明VCP在将WRNp从核仁释放中起机制性作用。对体外表达的各种VCP结构域和突变蛋白的免疫组织化学分析表明，VCP在其结构域结构内可能包含几个分级的细胞定位基序。
