Molecular Determinants of AGRP Function

AGRP 功能的分子决定因素

• 批准号: 7065653
• 负责人: GLENN L MILLHAUSER
• 金额: $ 26.22万
• 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 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7065653
• 关键词: cell surface receptors; chemical stability; chimeric proteins; crosslink; cystine; gene mutation; hormone inhibitor; hormone receptor; melanocyte stimulating hormone; neuropeptide receptor; nuclear magnetic resonance spectroscopy; peptide library; photoactivation; pigmentation; protein engineering; protein folding; protein isoforms; protein structure function; receptor binding; receptor sensitivity; syndecan; tissue /cell culture

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）：