Characterization and comparison of protein complexes initiated by the intracellular domain of individual Notch paralogs
Characterization and comparison of protein complexes initiated by the intracellular domain of individual Notch paralogs
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DOI：
10.1016/j.bbrc.2011.03.042
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发表时间：
2011-04-15
影响因子：
3.1
通讯作者：
Hendzel, Michael J.
中科院分区：
文献类型：
--
作者：
Han, Jianxun;Allalunis-Turner, Joan;Hendzel, Michael J.
Notch信号通路对于胚胎发育、器官发生和组织稳态是必不可少的。Notch信号异常与几种类型的癌症有关。Notch受体的活性形式是其胞内结构域（NICD），其在配体结合后通过一系列蛋白水解裂解从细胞膜释放。NICD对细胞表型的剂量依赖性效应已在几种条件下观察到，但其潜在机制尚未得到很好的研究。此外，有四种哺乳动物Notch旁系同源物具有冗余和独特的功能。这种变异性的分子基础也没有得到很好的理解。在这项研究中，我们使用尺寸排阻色谱法，以检查整体分布的NICD之间的NICD含有蛋白质复合物的条件下，增加NICD丰度。我们发现NICD蛋白复合物的组装是剂量依赖性的，并且典型复合物的丰度受限于MAML，MAML是参与典型NICD反式激活复合物形成的蛋白质之一，其随着NICD丰度的增加而饱和。此外，N4 ICD在4种NICD中显示出独特的洗脱曲线。这些结果有助于解释NICD活性的剂量依赖性。这些结果为开发新的试剂阻断Notch信号传导以获得治疗益处提供了信息。(C)2011 Elsevier Inc. All rights reserved.
The Notch signaling pathway is essential for embryonic development, organogenesis, and tissue homeostasis. Aberrant Notch signaling is associated with several types of cancers. The active form of Notch receptor is its intracellular domain (NICD), which is released from the cell membrane by serial proteolytic cleavages following ligand binding. Dose-dependent effects of NICD on cellular phenotypes have been observed under several conditions although the underlying mechanisms have not been well studied. Moreover, there are four mammalian Notch paralogs that have redundant as well as unique functions. The molecular basis for this variability is also not well understood. In this study, we used size exclusion chromatography to examine the overall distribution of NICD among NICD-containing protein complexes under conditions of increasing NICD abundance. We found that the assembly of NICD protein complexes was dose-dependent and that the abundance of the canonical complex limited by, MAML, one of the proteins involved in the formation of canonical NICD transactivation complex, which became saturated with increasing NICD abundance. In addition, N4ICD showed a unique elution profile among the four NICDs. These results help to explain the dose-dependent and activities of NICD. These results are informative for the development of new reagents block Notch signaling for therapeutic benefit. (C) 2011 Elsevier Inc. All rights reserved.