SPECTRIN-LIKE PROTEIN IN BRAIN

这个实验室的长期目标是了解它的结构， 鬼影蛋白亚型在哺乳动物脑中的位置和功能。在 上一次授权期，我们确定了三种脑影蛋白亚型：[1]脑 血影蛋白(240/235)，发现于轴突和神经元胞体，[2]脑 血影蛋白(240/235E)是一种存在于神经元中的红系样异构体 胞体和树突以及少突胶质细胞，以及[3]脑 SPECTIN(240/235A)，仅定位于星形胶质细胞胞体和 流程。我们还鉴定了两个9 kb和11 kb的β-血影蛋白mRNAs 小鼠脑中的大小为KB。通过对cDNA的克隆和测序，我们已经 获得了大于50%的推导出的9kb mRNA序列(即 我们认为是240/235E的Beta亚基)。在下一次拨款期间 在此期间，我们将完成9kb和11kb的记录序列； 鉴定与突触小泡结合的血影蛋白亚型特异性 (突触素I)和锚蛋白，利用细菌表达的片段 9kb和11kb的Beta光谱蛋白；鉴定最小结合序列和 缺失结合突触小泡和锚蛋白的必需氨基酸 β-血影蛋白基因的突变和定点突变 确定突触小泡与脑光谱的相互作用 通过突触蛋白I，受钙离子和钙调蛋白的调节(新的特异性靶点)。AS 小的球形突触小泡似乎附着在活动区。 对突触前质膜的作用，新增加的特异性 AIM对于我们理解钙离子调节的胞吐作用是必不可少的 神经末梢内的神经递质。首席调查员和 他的同事发表了60篇关于大脑的科学文章和摘要 上一次资助期内的血影蛋白和相关分子(1986- 1991年)。

A long term objective of this laboratory is to understand the structure, location and functions of spectrin isoforms within mammalian brain. In the last grant period we identified three brain spectrin isoforms: [1] brain spectrin(240/235) which is found in axons and neuronal soma, [2] brain spectrin(240/235E) which is an erythroid-like isoform found in neuronal soma and dendrites as well as oligodendrocytes, and [3] brain spectrin(240/235A) which is located exclusively in astrocyte soma and processes. We have also identified two beta spectrin mRNAs of 9 Kb and 11 Kb size in mouse brain. Through cloning and sequencing of cDNA, we have obtained greater than 50% of the deduced sequence of the 9 Kb mRNA (which we believe to be the beta subunit of 240/235E). During the next grant period, we will complete the sequence of the 9 Kb and 11 Kb transcripts; identify the spectrin isoform specificity for binding of synaptic vesicles (synapsin I) and ankyrin, utilizing bacterially expressed segments of the 9 Kb and 11 Kb beta spectrins; identify the minimal binding sequence and essential amino acids for binding synaptic vesicles and ankyrin by deletion mutagenesis and site specific mutagenesis of beta spectrin cDNA, and determine whether the interaction of synaptic vesicles with brain spectrin via synapsin I is regulated by Ca2+ and calmodulin (new specific aim). As small spherical synaptic vesicles appear to be attached to the active zone of the presynaptic plasma membrane by spectrin, the newly added specific aim is essential to our understanding of Ca2+ regulated exocytosis of neurotransmitter within the nerve terminal. The Principal Investigator and his coworkers published 60 scientific articles and abstracts on brain spectrin and related molecules during the previous grant period (1986- 1991).