Structural Determination of the E-Related Region of the TGFbeta type III receptor

TGFbeta III 型受体 E 相关区域的结构测定

• 批准号: 7632120
• 负责人: THOMAS KEENAN MILLSTEAD
• 金额: $ 2.47万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-01-05
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7632120
• 关键词: Affinity; Amino Acids; Binding; Binding Sites; C-terminal; Cleaved cell; Cleft Palate; Complement; Complex; Crystallization; Crystallography; Development; Distal; Electrophoretic Mobility Shift Assay; Endoglin; Extracellular Domain; Growth Factor; Hand; Human; Knockout Mice; Label; Ligand Binding; Membrane; N-terminal; NMR Spectroscopy; Odontogenic Tumors; Phosphorylation; Play; Protein Isoforms; Proteoglycan; Recruitment Activity; Role; Sampling; Series; Side; Signal Transduction; Site-Directed Mutagenesis; Solutions; Structure; Surface Plasmon Resonance; TGF beta type III receptor; TGFB1 gene; TGFB2 gene; Tooth structure; Transforming Growth Factor beta; Transmembrane Domain; UMOD gene; Vertebral column; craniofacial; extracellular; inhibin; insight; member; polypeptide; receptor; research study; three dimensional structure; tumorigenesis

DESCRIPTION (provided by applicant): The transforming growth factor beta (TGF?) superfamily is composed of 42 structurally related polypeptide growth factors that perform various functions in humans. All of the members of the TGF3 superfamily signal through a distinct set of extracellular receptors commonly known as the type I and type II receptors. The prototypic members of the superfamily are the TGF?s: TGFB?1, 2, and 3. Signaling is initiated when the igand binds to the type II receptor with subsequent recruitment of the type I receptor forming the mature signaling complex. Both TGF?1 and 3 have intrinsically high affinity for the type II receptor (T?RII) and are able to initiate signaling without any assistance. TGF?2, on the other hand, binds very weakly to the type II receptor. The intrinsically low binding affinity of TGF?2 for TBRII is compensated through the use of an accessory receptor, betaglycan. Betaglycan's role in TGF?2 signaling is to present TGF?2 to T?RII by increasing the intrinsically low affinity of TGF?2 for T(3RII through the formation of a TGF?2:betaglycan:TBRII ternary complex. The TGF? type I receptor (T?RI) is recruited to the complex, betaglycan is displaced, forming the mature signaling complex. Although it is known that betaglycan is required for TGF?2 signaling, the mechanism of complex assembly is not. Betaglycan's extracellular domain is composed of two separate sub-domains, each capable of promoting TGF(3 induced rSMAD phosphorylation. Implying that each half of the extracellular domain betaglycan can independently present TGF?2 to T?RII. The membrane-distal half is referred to as the endoglin-related region (BGE) and the membrane-proximal half is referred to as uromodulin-related region (BGU). While both regions are able to bind TGFB, BGU is also capable of binding inhibin. In combination with the fact that inhibin binding is solely restricted to BGU, it also implies that each half may play a different role in TGF 3 signaling. BGE was selected for study since it is solely capable promoting TGF?2 signaling. To further our understanding of betaglycan's mechanism of presentation, the solution structure of the Endoglin-related region of betaglycan (BGE) will be determined using solution NMR spectroscopy with the complementing crystal structure of BGE in complex with TGFB2 and T?RII. In parallel, native gel shift assays and surface plasmon resonance binding studies will be used to examine the influence BGE has on the binding of T?RII. TGF?2 has been found to play crucial roles in tooth development, it has also been implicated in tumorigenesis of odontogenic neoplasms, and TGF?2 knockout mice develop cleft palate. Understanding the structural and functional role betaglycan plays in TGF(32 signaling, it will give vital insight into craniofacial development.

描述（申请人提供）：转化生长因子β (TGF?)超家族由42个结构相关的多肽生长因子组成，在人体中发挥多种功能。TGF3超家族的所有成员都通过一组不同的细胞外受体（通常称为I型和II型受体）进行信号传递。超家族的原型成员是TGF？TGFB吗?1 2 3。当配体与II型受体结合并随后募集I型受体形成成熟的信号复合物时，信号传导就开始了。TGF ?1和3对II型受体(T？RII)，能够在没有任何帮助的情况下发起信号。TGF吗?另一方面，2与II型受体的结合非常弱。TGF?的内在低结合亲和力2对于TBRII是通过使用辅助受体- β多糖来补偿的。β -多糖在TGF？2信号是呈递TGF？2到T？RII通过增加TGF？2为T（3RII）通过TGF？2: β多糖：三三元配合物。TGF吗?型受体(T？RI)被招募到复合物中，β多糖被置换，形成成熟的信号复合物。虽然我们知道TGF？2 .信号转导，复杂装配的机制是没有的。Betaglycan的胞外结构域由两个独立的子结构域组成，每个子结构域都能促进TGF(3)诱导的rSMAD磷酸化。这意味着细胞外结构域β -多糖的每一半都可以独立呈递TGF？2到T？RII。膜的远端部分称为内啡肽相关区（BGE），膜的近端部分称为尿调素相关区（BGU）。虽然这两个区域都能结合TGFB，但BGU也能结合抑制素。结合抑制素仅与BGU结合的事实，这也暗示了每一半在TGF 3信号传导中可能发挥不同的作用。之所以选择BGE作为研究对象，是因为BGE仅能促进TGF？2信号。为了进一步了解betaglycan的呈现机制，我们将利用溶液核磁共振波谱法确定betaglycan （BGE）的endoglin相关区域的溶液结构，BGE与TGFB2和T？RII。同时，将使用天然凝胶移位试验和表面等离子体共振结合研究来检查BGE对T？RII。TGF吗?2在牙齿发育中起着至关重要的作用，它也与牙源性肿瘤的发生有关，TGF？2只基因敲除小鼠出现腭裂。了解β多糖在TGF（32）信号传导中的结构和功能作用，将为颅面发育提供重要的认识。