Suppr超能文献

在昆虫神经系统中表达的生长阻滞肽——克隆与功能特性分析

Growth-blocking peptide expressed in the insect nervous system--cloning and functional characterization.

作者信息

Hayakawa Y, Noguchi H

机构信息

Biochemical Laboratory, Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.

出版信息

Eur J Biochem. 1998 May 1;253(3):810-6. doi: 10.1046/j.1432-1327.1998.2530810.x.

Abstract

Growth-blocking peptide (GBP) is an insect biogenic peptide that retards larval growth and, consequently, delays the onset of pupation of lepidopteran larvae. Transcription of the GBP gene has been proven to be regulated in a tissue-dependent manner by an approximately 0.8-kb mRNA transcript in fat body and 2.5-kb transcript in the brain central nervous system (CNS) [Hayakawa, Y., Ohnishi, A., Yamanaka, A., Izumi, S. & Tomino, S. (1995) FEBS Lett. 367, 185-189]. The GBP cDNA in the brain CNS was isolated, sequenced and found to be almost identical with that in the fat body, except that it encodes a long 5'-untranslated region (approximately 1.1 kb), thus indicating that the brain CNS is synthesized as a polyprotein precursor and released through posttranslational processing in the same manner as that predicted in the fat body. Sequence analyses of the genomic GBP gene fragments demonstrated that the 5'-untranslated region contains an intron encoding a sequence element, TGATAA, which has been reported to be important for expression in the insect larval fat body, suggesting that this element contributes to a tissue-specific expression of the shorter GBP mRNA in fat body. Ribonuclease protection assays showed that parasitization by a parasitic wasp elevated the expression of GBP mRNA in brain CNS. The parasitization-induced increase of GBP precursor and GBP concentrations was also demonstrated in brain CNS. Brain CNS dopamine was increased eightfold by incubating the tissue with GBP for 8 h through the elevation of dopa decarboxylase activity by a transcriptional enhancement perhaps due to GBP-induced increase of cytoplasmic Ca2+ concentration. Dopamine elevation reduced in vitro incorporation of methionine into proteins synthesized in brain CNS.

摘要

生长阻滞肽(GBP)是一种昆虫生物源肽,它会抑制幼虫生长,从而延迟鳞翅目幼虫化蛹的开始。GBP基因的转录已被证明在脂肪体中受约0.8 kb的mRNA转录本以组织依赖性方式调控,在脑中枢神经系统(CNS)中受2.5 kb转录本调控[Hayakawa, Y., Ohnishi, A., Yamanaka, A., Izumi, S. & Tomino, S. (1995) FEBS Lett. 367, 185 - 189]。脑CNS中的GBP cDNA被分离、测序,发现它与脂肪体中的几乎相同,只是它编码一个长的5'非翻译区(约1.1 kb),因此表明脑CNS是作为多蛋白前体合成的,并通过与脂肪体中预测的相同方式进行翻译后加工释放。基因组GBP基因片段的序列分析表明,5'非翻译区包含一个编码序列元件TGATAA的内含子,据报道该元件对昆虫幼虫脂肪体中的表达很重要,这表明该元件有助于脂肪体中较短GBP mRNA的组织特异性表达。核糖核酸酶保护试验表明,寄生蜂寄生会提高脑CNS中GBP mRNA的表达。在脑CNS中也证实了寄生诱导的GBP前体和GBP浓度增加。通过将组织与GBP孵育8小时,脑CNS中的多巴胺增加了八倍,这可能是由于GBP诱导细胞质Ca2 +浓度增加,通过转录增强提高了多巴脱羧酶活性。多巴胺升高减少了蛋氨酸在脑CNS中合成蛋白质的体外掺入。

文献检索

告别复杂PubMed语法,用中文像聊天一样搜索,搜遍4000万医学文献。AI智能推荐,让科研检索更轻松。

立即免费搜索

文件翻译

保留排版,准确专业,支持PDF/Word/PPT等文件格式,支持 12+语言互译。

免费翻译文档

深度研究

AI帮你快速写综述,25分钟生成高质量综述,智能提取关键信息,辅助科研写作。

立即免费体验