RECEPTOR CRYSTALLOGRAPHY

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。我们的项目有两个目标：一个是确定Notch受体在配体诱导信号之前如何保持静止构象，另一个是确定Notch在细胞内形成的转录复合体的结构。Noch在整个发育过程中对细胞命运的决定起着关键作用。当一个细胞上表达的DSL家族的配体与相邻细胞上的Notch受体结合时，通常会诱导Notch信号。Notch受体的负调节区由一系列Notch特有的LIN12/Notch(LNR)重复序列和一个新的结构域HD(异二聚化区)组成，维持Notch受体的静止构象，我们正在努力解决不同Notch受体负调节区的结构。已知的唯一激活Notch的效应功能是由转录复合体介导的。我们有晶体，包括CSL(DNA结合蛋白)，Notch(锚蛋白重复序列和RAM区)，MasterMind(DNA上的共激活因子)。我们先前已经在没有RAM区域的情况下解决了这个复合体的结构(Nam等人，Cell 2006)，现在我们已经加入了RAM的额外关键多肽部分，以确定这个Notch特异性结构域在复合体中的哪里结合。我们正在努力改进包括RAM结构域的络合物的晶体，以建立包括RAM区域的络合物的高质量原子模型。此外，我们打算将其他与RAM竞争的域也加入到建筑群中来绑定CSL。确定这些复合体的结构将有助于揭示Notch结合将CSL从抑制子转换为激活子的机制。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our project has two goals: one is to determine how Notch receptors are maintained in a resting conformation prior to the induction of signaling by ligands, and the other is to determine the structure of transcription complexes formed by intracellular Notch. Notch plays a key role in cell fate decisions throughout development. Notch signals are normally induced when a ligand of the DSL family expressed on one cell binds to a Notch receptor on a neighboring cell. The negative regulatory region of Notch receptors, which consists of a series of Notch-unique LIN12/Notch (LNR) repeats and a novel domain called HD (for heterodimerization region), maintains Notch receptors in their resting conformation, and we are working on solving the structures of the negative regulatory regions of different Notch receptors. The only known effector functions of activated Notch are mediated by the transcriptional complex. We have crystals that include CSL (DNA-binding protein), Notch (ankyrin repeats and RAM region), Mastermind (co-activator) on DNA. We have previously solved the structure of this complex without the RAM region (Nam et al., Cell 2006), and we now have incorporated the additional key peptide portion of RAM to determine where this Notch-specific domain binds in the complex. We are working on improving the crystals of complexes that include the RAM domain to build a good quality atomic model of complexes that include the RAM region. Moreover, we intend to incorporate other domains that compete with RAM to bind CSL into the complex as well. Determining the structures of these complexes will shed light on the mechanism by which Notch binding switches CSL from a repressor to an activator.