Nuclear α Spectrin Differentially Affects Monoubiquitinated Versus Non-Ubiquitinated FANCD2 Function After DNA Interstrand Cross-Link Damage.
Nuclear α Spectrin Differentially Affects Monoubiquitinated Versus Non-Ubiquitinated FANCD2 Function After DNA Interstrand Cross-Link Damage.
复制标题
DNA 链间交联损伤后，核 α 血影蛋白对单泛素化与非泛素化 FANCD2 功能的影响不同。
DOI：
10.1002/jcb.25352
复制
发表时间：
2016
影响因子：
4
通讯作者：
Lambert,MurielW
中科院分区：
文献类型：
--
作者：
Zhang,Pan;Sridharan,Deepa;Lambert,MurielW
非红细胞α血影蛋白（αIISp）和范科尼贫血（FA）蛋白FANCD 2在S期DNA链间交联（ICL）修复中发挥关键作用。两者都是招募修复蛋白（如XPF）到ICL损伤和修复部位所必需的。然而，它们在ICL修复中的关系以及αIISp是否参与FANCD 2在修复中的功能尚不清楚。目前的研究表明，ICL形成后，FANCD 2与αIISp分离，并在αIISp之前定位于核灶中的损伤部位。αIISp和FANCD 2灶不共定位，与我们先前的发现相反，αIISp和ICL修复蛋白XPF共定位，并遵循相似的形成时间过程。αIISp的敲低对FANCD 2（FANCD 2-Ub）的单泛素化或其在染色质或病灶中的定位没有影响，尽管它会导致ICL修复减少。使用ICL修复和αIISp缺陷的FA患者细胞的研究阐明了αIISp在非Ub FANCD 2功能中的重要作用。在FA互补A组（FA‐A）细胞中，FANCD 2没有被单泛素化，也没有形成损伤诱导的病灶，我们证明，通过敲低蛋白酶μ‐钙蛋白酶，αIISp水平恢复正常，导致ICL损伤后形成非Ub FANCD 2病灶。由于FA‐A细胞中αIISp水平的恢复恢复了DNA修复和细胞存活，我们认为αIISp对于将非Ub FANCD 2募集到损伤部位至关重要，这在修复反应和ICL修复中具有重要作用。J.细胞。117：671-683，2016.© 2015威利期刊公司.
Nonerythroid α spectrin (αIISp) and the Fanconi anemia (FA) protein, FANCD2, play critical roles in DNA interstrand cross‐link (ICL) repair during S phase. Both are needed for recruitment of repair proteins, such as XPF, to sites of damage and repair of ICLs. However, the relationship between them in ICL repair and whether αIISp is involved in FANCD2's function in repair is unclear. The present studies show that, after ICL formation, FANCD2 disassociates from αIISp and localizes, before αIISp, at sites of damage in nuclear foci. αIISp and FANCD2 foci do not co‐localize, in contrast to our previous finding that αIISp and the ICL repair protein, XPF, co‐localize and follow a similar time course for formation. Knock‐down of αIISp has no effect on monoubiquitination of FANCD2 (FANCD2‐Ub) or its localization to chromatin or foci, though it leads to decreased ICL repair. Studies using cells from FA patients, defective in ICL repair and αIISp, have elucidated an important role for αIISp in the function of non‐Ub FANCD2. In FA complementation group A (FA‐A) cells, in which FANCD2 is not monoubiquitinated and does not form damage‐induced foci, we demonstrate that restoration of αIISp levels to normal, by knocking down the protease μ‐calpain, leads to formation of non‐Ub FANCD2 foci after ICL damage. Since restoration of αIISp levels in FA‐A cells restores DNA repair and cell survival, we propose that αIISp is critical for recruitment of non‐Ub FANCD2 to sites of damage, which has an important role in the repair response and ICL repair. J. Cell. Biochem. 117: 671–683, 2016. © 2015 Wiley Periodicals, Inc.