SPECTRIN-LIKE PROTEIN IN BRAIN

这个实验室的一个长期目标是了解结构， 血影蛋白异构体在哺乳动物脑内的位置和功能。 在 在上一个资助期，我们鉴定了三种脑血影蛋白亚型：[1]脑血影蛋白 血影蛋白（240/235），见于轴突和神经元索马[2]，脑 血影蛋白（240/235 E），其是在神经元中发现的红细胞样同种型， 索马和树突以及少突胶质细胞和[3]脑 血影蛋白（240/235 A），其仅位于星形胶质细胞索马体中， 流程. 我们还鉴定了两种β血影蛋白mRNA，分别为9 Kb和11 kb， 小鼠脑中的KB大小。 通过cDNA的克隆和测序， 获得了大于50%的9 Kb mRNA的推导序列（ 我们认为是240/235 E的β亚基）。 在下一次赠款期间 期间，我们将完成9 Kb和11 Kb转录本的测序; 鉴定血影蛋白同种型结合突触囊泡的特异性 （突触蛋白I）和锚蛋白，利用突触蛋白的细菌表达片段， 9 Kb和11 Kb β血影蛋白;鉴别最小结合序列， 通过缺失结合突触囊泡和锚蛋白的必需氨基酸 β血影蛋白cDNA的诱变和位点特异性诱变，和 确定突触囊泡与脑血影蛋白的相互作用 通过突触蛋白I由Ca 2+和钙调蛋白调节（新的特异性目标）。 作为 小的球形突触囊泡似乎附着在活动区 的突触前质膜的血影蛋白，新增加的具体 目的对于我们理解Ca 2+调节的胞吐作用是至关重要的。 神经末梢内的神经递质。 主要研究者和 他的同事发表了60篇关于大脑的科学文章和摘要 血影蛋白和相关分子在上一个资助期（1986年- 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).