THE ROLE OF TOMOSYN-2 IN INSULIN SECRETION

描述(申请人提供)：2型糖尿病(T2D)在西方社会正在达到流行的程度。当胰腺的？细胞不能分泌足够的胰岛素来适当地调节外周血糖水平时，T2D就会发生，通常是在肥胖的情况下 以及与之相关的外周胰岛素抵抗。胰岛素分泌的机制还不是很清楚。利用正向遗传学方法，我们发现Tomosyn-2基因蛋白编码区的单核苷酸多态(SNP)与低血糖/高血糖表型直接相关。Tomosyn-2是一种相对不具特征的蛋白质，其调节胰岛素分泌的机制尚不清楚。在这个独立之路奖申请中提出的工作有两个主要目标：1)阐明Tomosyn-2调节胰岛细胞胰岛素分泌的机制；2)利用我在T2D研究这一新领域的发展，促进我的职业生涯从指导阶段发展到独立阶段。在资助的指导阶段，我将接受质谱学、体外脂质体融合分析、膜生物化学和Tomosyn-2基因敲除小鼠的生成方面的培训。在指导阶段进行的研究将检验已确定的磷酸化位点对Tomosyn-2调节胰岛素分泌能力的影响，并了解Tomosyn-2被靶向蛋白酶体降解的机制。在拨款的独立阶段，我的研究将研究Tomosyn-2通过调节可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体(SNARE)蛋白的活性来抑制胰岛素分泌的机制，并表征新型Tomosyn-2结合蛋白的作用。这些研究将为Tomosyn-2抑制胰岛素分泌的机制提供新的线索，并将加深我们对T2D中胰岛素分泌调节的理解。

DESCRIPTION (provided by applicant): Type 2 diabetes (T2D) is reaching epidemic proportions in Western societies. T2D occurs when the ß-cells of the pancreas do not secrete enough insulin to properly regulate peripheral blood glucose levels, usually in the face of obesity and associated peripheral insulin resistance. The mechanisms underlying insulin secretion are not properly understood. Using a forward genetics approach, we have discovered that a single nucleotide polymorphism (SNP) in the protein-coding region of the gene for tomosyn-2 is directly correlated with the hypoinsulinemic/hyperglycemic phenotype. Tomosyn-2 is a relatively uncharacterized protein and the mechanism by which it regulates insulin secretion is not known. The work proposed here in this Pathways to Independence Award application has two primary goals: 1) to elucidate the mechanism by which tomosyn-2 regulates insulin secretion in pancreatic ß-cells, and 2) to use my development of this novel area of T2D research to facilitate the development of my career from the mentored phase to an independent phase. During the mentored phase of the grant, I will receive training in mass spectrometry, in vitro liposome fusion assays, membrane biochemistry, and the generation of the tomosyn-2 knockout mouse. The research conducted in the mentored phase will examine the effect of identified phosphorylation sites on the ability of tomosyn-2 to regulate insulin secretion and to understand the mechanism by which tomosyn-2 is targeted for proteosomal degradation. During the independent phase of the grant, my research will examine the mechanism by which tomosyn-2 inhibits insulin secretion by regulating the activity of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and characterize the role of novel tomosyn-2 binding proteins. These studies will provide novel clues to the mechanism by which tomosyn-2 inhibits insulin secretion and will further our understanding of the regulation of insulin secretio in T2D.