Molecular Determinants of AGRP Function

AGRP 功能的分子决定因素

• 批准号: 7230448
• 负责人: GLENN L MILLHAUSER
• 金额: $ 25.42万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA CRUZ
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-15 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7230448
• 关键词: ART protein; Adopted; Affinity; Amino Acids; Anorexia; Architecture; Binding; Biochemical; Biological Assay; Body Weight; Brain; C-terminal; Cachexia; Cardiovascular Diseases; Cell surface; Chimera organism; Class; Condition; Cultured Cells; Cysteine; Cystine; Diabetes Mellitus; Disease; Energy Intake; Equilibrium; Exhibits; Expenditure; Foundations; Funding; G-Protein-Coupled Receptors; Goals; Grant; Heparan Sulfate Proteoglycan; Hypothalamic structure; Invertebrates; Investigation; Kinetics; Laboratories; Length; Ligands; Link; Malignant Neoplasms; Mediating; Membrane; Methodology; Molecular; Molecular Target; Mutagenesis; N-terminal; Neuraxis; Neuropeptides; Obesity; Phage Display; Pigmentation physiologic function; Plants; Positioning Attribute; Protein C; Proteins; Public Health; Receptor Signaling; Research; Role; Signal Transduction; Signaling Molecule; Skin; Societies; Structure; Structure of nucleus infundibularis hypothalami; Tertiary Protein Structure; Testing; Thermodynamics; Transgenic Animals; Transgenic Organisms; Vascular Diseases; Weight maintenance regimen; Work; agouti protein; alpha-Melanocyte stimulating hormone; base; comparative; concept; crosslink; design; energy balance; extracellular; inhibitor/antagonist; insight; melanocortin receptor; novel; programs; protein folding; protein function; receptor; receptor function; research study; scaffold; scale up; syndecan

DESCRIPTION (provided by applicant): Obesity is one of the greatest public health concerns facing Western society. The condition arises from an imbalance between energy intake and expenditure and contributes to diabetes, cardiovascular disease and cancer. In the brain, a key focal point for control of energy balance is melanocortin signaling, in which there are two ligands, alpha-melanocyte stimulating hormone and Agouti-related protein (AGRP). These molecules act in opposite ways through CNS melanocortin receptors (MCRs) to promote negative and positive energy balance, respectively. AGRP is a multi-domain protein with MCR activity concentrated in its unusual Cys-rich, C-terminal domain. The Pl's laboratory recently determined the structure of this domain and identified regions that are postulated to be essential for AGRP's ability to select MCRs of the central nervous system. The goal of this research program is to significantly broaden the understanding of MCR signaling by determining the molecular features of AGRP that confer its receptor selectivity and control over MCR function. Four Aims are proposed. 1) The structure of the homologous agouti protein that functions in pigmentation will be determined. Comparison of the AGRP and agouti structures will help to identify regions within these signaling molecules that control their respective MCR selectivity. 2) Protein design and photo crosslinking will be used to evaluate the MC receptor regions that make direct contact with AGRP. These studies will test the hypothesis that a specific loop in AGRP mediates MCR recognition. 3) The structure and function of the AGRP N-terminal domain will be determined. Recent findings suggest that this region potentiates MCR antagonism by binding to cell surface syndecans. This concept will be tested using structure-guided pharmacological and transgenic methodologies. 4) The stability and design potential of the novel AGRP cystine-knot structure will be evaluated. The specific scaffold of the AGRP C-terminus has not been previously identified in mammalian proteins. However, studies with plant and invertebrate cystineknots suggest that this scaffold is ideal for pharmacological design. Thermodynamic studies will examine stability and phage display will be used to develop a cystine-knot that selects for receptors outside of the MCR class.

描述(由申请人提供)： 肥胖是西方社会面临的最大公共健康问题之一。这种情况是由于能量摄入和消耗之间的不平衡造成的，并导致糖尿病、心血管疾病和癌症。在大脑中，控制能量平衡的一个关键焦点是黑素皮质素信号，其中有两个配体，即α-黑素细胞刺激素和刺激物相关蛋白(AGRP)。这些分子通过中枢神经系统黑素皮质素受体(MCRs)以相反的方式发挥作用，分别促进正负能量平衡。AgRP是一个多结构域的蛋白质，其MCR活性集中在其不寻常的富含Cys的C末端结构域。Pl的实验室最近确定了这个结构域的结构，并确定了对AGRP选择中枢神经系统MCRs的能力至关重要的区域。这项研究的目的是通过确定AGRP的分子特征来显著拓宽对MCR信号的理解，这些分子特征赋予其受体选择性和对MCR功能的控制。提出了四个目标。1)将确定在色素形成中起作用的同源刺参蛋白的结构。AGRP和AGUTY结构的比较将有助于确定这些信号分子中控制各自MCR选择性的区域。2)蛋白质设计和光交联将用于评估与AGRP直接接触的MC受体区域。这些研究将检验AGRP中特定环路介导MCR识别的假设。3)将确定AGRP N-末端结构域的结构和功能。最近的发现表明，该区域通过与细胞表面突触蛋白结合来增强MCR的拮抗作用。这一概念将使用结构导向的药理学和转基因方法进行测试。4)对新型AGRP半胱氨酸结结构的稳定性和设计潜力进行了评估。以前还没有在哺乳动物的蛋白质中鉴定出AGRP C末端的特定支架。然而，对植物和无脊椎动物的囊结的研究表明，这种支架是药物设计的理想材料。热力学研究将检验稳定性，噬菌体展示将用于开发一种选择MCR类以外受体的半胱氨酸结。