Fibronectin-tissue transglutaminase matrix rescues RGD-impaired cell adhesion through syndecan-4 and β1 integrin co-signaling
Fibronectin-tissue transglutaminase matrix rescues RGD-impaired cell adhesion through syndecan-4 and β1 integrin co-signaling
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DOI：
10.1074/jbc.m801763200
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发表时间：
2008-07-25
影响因子：
4.8
通讯作者：
Griffin, Martin
中科院分区：
文献类型：
--
作者：
Telci, Dilek;Wang, Zhuo;Griffin, Martin
人类ChlR1 （hChlR1）是DEAD/DEAH解旋酶亚家族的一员，被证明与内聚复合物的组分相互作用，并在姐妹染色单体内聚中发挥作用。为了研究hChlR1的生化和生物学特性，我们从293细胞中纯化了该蛋白，并证明了hChlR1具有dna依赖性atp酶和解旋酶活性。在ATP存在的情况下，这种解旋酶在单链DNA上沿5‘到3’方向易位，在较小程度上，也有dATP存在。它的解绕活性需要一个5'-单链区域来装载解旋酶，因为顺流端双链结构不支持解绕。hChlR1的解旋酶活性能够取代高达100 bp的双链区域，通过RPA或内聚建立因子Ctf18-RFC（复制因子C）复合物可以将其扩展到500 bp。我们发现hChlR1与hCtf18-RFC复合物、人类增殖细胞核抗原和hFen1相互作用。Fen1和hChlR1之间的相互作用刺激了Fen1的皮瓣内切酶活性。通过靶向小干扰RNA处理选择性地耗尽hclr1或Fen1可导致姐妹染色单体过早分离。这些发现与hChlR1在姐妹染色单体内聚建立中的作用一致，并表明其作用可能有助于在内聚中重要的滞后链加工事件。
Human ChlR1 (hChlR1), a member of the DEAD/DEAH subfamily of helicases, was shown to interact with components of the cohesin complex and play a role in sister chromatid cohesion. In order to study the biochemical and biological properties of hChlR1, we purified the protein from 293 cells and demonstrated that hChlR1 possesses DNA-dependent ATPase and helicase activities. This helicase translocates on single-stranded DNA in the 5' to 3' direction in the presence of ATP and, to a lesser extent, dATP. Its unwinding activity requires a 5'-single-stranded region for helicase loading, since flush-ended duplex structures do not support unwinding. The helicase activity of hChlR1 is capable of displacing duplex regions up to 100 bp, which can be extended to 500 bp by RPA or the cohesion establishment factor, the Ctf18-RFC (replication factor C) complex. We show that hChlR1 interacts with the hCtf18-RFC complex, human proliferating cell nuclear antigen, and hFen1. The interactions between Fen1 and hChlR1 stimulate the flap endonuclease activity of Fen1. Selective depletion of either hChlR1 or Fen1 by targeted small interfering RNA treatment results in the precocious separation of sister chromatids. These findings are consistent with a role of hChlR1 in the establishment of sister chromatid cohesion and suggest that its action may contribute to lagging strand processing events important in cohesion.