ENZYMATIC MECHANISMS OF UBIQUITIN-LIKE PROTEIN CONJUGATION

泛素样蛋白缀合的酶促机制

• 批准号: 8169265
• 负责人: BRENDA A SCHULMAN
• 金额: $ 0.52万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8169265
• 关键词: Binding; C-terminal; CUL1 gene; Cell physiology; Computer Retrieval of Information on Scientific Projects Database; Cullin Proteins; Cysteine; Ensure; Family; Funding; Goals; Grant; Human; Institution; Ligase; Mediating; Pathway interactions; Proteins; RBX1 gene; Regulation; Reporting; Research; Research Personnel; Resources; Site-Directed Mutagenesis; Source; Specificity; Substrate Interaction; Ubiquitin; Ubiquitin Like Proteins; Ubiquitination; United States National Institutes of Health; Vertebrates; cell growth regulation; inhibitor/antagonist; prevent; receptor; thioester; ubiquitin-protein ligase

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. Cullin RING ligases (CRLs) comprise the largest subfamily of E3 ubiquitin ligases. In humans, six cullins (CUL1, 2, 3, 4A, 4B, and 5), two RBX-family RING proteins (RBX1 and 2), and hundreds of substrate receptors assemble into distinct CRLs that mediate ubiquitination of thousands of targets to regulate a vast array of cellular processes. CRL function is regulated by attachment of the ubiquitin-like protein (UBL) NEDD8 to a conserved Lys in a cullin's C-terminal domain. NEDD8 both enhances intrinsic CRL ubiquitination activity, and prevents CRL binding to the inhibitor CAND1. At present, the NEDD8 cascade is known to contain a single E1 (NAE1-UBA3), which activates NEDD8 and ultimately catalyzes transfer of NEDD8's C-terminus to the catalytic cysteine of the characterized NEDD8 E2, UBE2M (also known as UBC12). The resulting UBE2M~NEDD8 thioester conjugate serves as the direct source of NEDD8 to be covalently attached to a cullin's acceptor Lys. Despite the importance of CRL activation by NEDD8, it remains unknown whether there is any specificity in cullin NEDD8ylation, or how such specificity could be established. Clues to selectivity might come from analogy to the ubiquitin (Ub) pathway. In vertebrates, the Ub pathway comprises two E1s, tens of E2s and hundreds of E3s promoting Ub transfer to thousands of targets. Within this hierarchy, E1-E2 and E2-E3-substrate interactions are highly specific to ensure precise temporal and spatial regulation of targets by modification with appropriate Ub linkages, which in turn mediate particular downstream functions. In contrast to the Ub pathway, the NEDD8 conjugation cascade was been reported to contain only a single E2. Given the important and diverse CRL functions in cellular regulation, our goal is to understand whether, and if so how, the NEDD8 cascade is equipped with additional levels of selectivity for cullin NEDD8ylation.

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 库林环连接酶(CRL)是E3泛素连接酶中最大的亚家族。在人类中，六个Cullins(CUL1，2，3，4A，4B和5)，两个RBX家族环蛋白(RBX1和2)，以及数百个底物受体组装成不同的CRL，介导数千个靶标的泛素化，调节大量的细胞过程。CRL的功能是通过将泛素样蛋白(UBL)NEDD8与cullin的C-末端结构域中保守的Lys结合来调节的。NEDD8既增强了CRL的内在泛素化活性，又阻止了CRL与抑制剂CAND1的结合。目前，已知的NEDD8级联中只有一个E1(NAE1UBA3)，它激活NEDD8，最终催化NEDD8‘S的C末端转移到NEDD8E2的催化半胱氨酸UBE2M(也称为UBC12)。得到的UBE2M~NEDD8硫酯结合物是NEDD8的直接来源，NEDD8将共价连接到cullin的受体Lys上。 尽管NEDD8激活CRL很重要，但目前还不清楚cullin NEDD8的激活是否有任何特异性，或者这种特异性是如何建立的。选择性的线索可能来自与泛素(Ub)途径的类比。在脊椎动物中，Ub途径由两个E1、数十个E2和数百个E3组成，促进Ub向数千个靶点转移。在这个层次中，E1-E2和E2-E3与底物的相互作用具有高度的特异性，通过适当的Ub连接进行修饰，确保对靶标的精确的时间和空间调节，这反过来又介导了特定的下游功能。 与Ub途径相反，NEDD8结合级联被报道只包含一个E2。鉴于CRL在细胞调控中的重要和多样化的功能，我们的目标是了解NEDD8级联是否以及如果是的话，为cullin NEDD8活化配备了额外的选择性水平。