MINTS AND SYNAPTIC VESICLE AND APP TRAFFICKING

描述（改编自申请人摘要）：本提案的目的是研究薄荷蛋白是否是突触囊泡和淀粉样前体蛋白（APP）运输的生理调节剂，目标是神经元突触前末端的活跃区。Mint1和Mint2是脑特异性蛋白，与突触囊泡胞外分泌所需的蛋白Munc18-1具有高亲和力。Mint的独特结构由一个N端Munc18-1结合域、一个中间磷酸酪氨酸结合域（PTB）和两个c端PDZ结构域组成，这表明它可能在胞吐前突触囊泡的靶向和对接反应中发挥重要作用。特别有趣的是，薄荷蛋白还与APP结合，APP是淀粉样蛋白β 4的亲本蛋白，是阿尔茨海默病发病机制的主要组成部分。由于尚不清楚细胞内APP运输是如何调节的，因此研究Mint蛋白的作用是一项重要的研究。因此，具体目的是：(1)通过转染Mint缺失突变体在海马神经元培养中研究Mint结构域的作用；(2)利用Cre/lox重组系统，通过基因诱导靶向研究Mints在小鼠体内的功能。

DESCRIPTION (Adapted from applicant's abstract): The goal of this proposal is to investigate whether Mint proteins are physiological regulators of synaptic vesicle and amyloid precursor protein (APP) trafficking targeted to the active zone of the presynaptic terminal of neurons. Mint1 and Mint2 are brain-specific proteins and bind with high affinity to Munc18-1, a protein required for synaptic vesicle exocytosis. The unique structure of Mint composed of an N- terminal Munc18-1 binding domain, a middle phosphotyrosine-binding (PTB) domain and two C-terminal PDZ domains, thus suggests that it may play an essential role in targeting and docking reactions of synaptic vesicles prior to exocytosis. Of particular interest, Mint proteins also bind to APP, the parent protein for amyloid protein beta4, a major component in the pathogenesis of Alzheimer's disease. Since it is not known how intracellular APP trafficking is regulated, investigating the role of Mint proteins is an important study to pursue. Therefore, the specific aims are: (1) to study the role of Mint domains by transfection of Mint deletion mutants in hippocampal neuronal cultures; (2) to study the function of Mints in mice by gene-inducible targeting using the Cre/lox recombination system.