摘要
谷胱甘肽-S-转移酶(GSTs)是一个功能广泛的超基因家族,其中Zeta家族在动物、植物和细菌中均有分布。在哺乳动物中,Zeta GSTs具有马来酰乙酰乙酸异构酶(MAAI)活性,参与苯丙氨酸/酪氨酸的代谢过程。本研究对家蚕Bombyxmori基因组中预测的GST基因(BmGSTz1)进行了表达序列标签的搜索,经拼接后获得一条含有3′和5′非翻译区在内的长度为1239bp的cDNA序列,其3′端含有AATAAA加尾信号。BmGSTz1基因含有4个内含子,外显子/内含子边界均符合GT-AG规则。经TA克隆证实,BmGSTz1基因编码区序列全长648bp,共编码215个氨基酸。BmGSTz1推定的分子量为24.8kD,等电点pI为8.06。BmGSTz1与其他昆虫和哺乳动物GSTz1的氨基酸序列高度保守,进化分析表明家蚕BmGSTz1与黑腹果蝇Drosophila melanogaster、冈比亚按蚊Anopheles gambiae、意大利蜜蜂Apismellifera和赤拟谷盗Tribolium castaneum的GSTz1形成1∶1∶1∶1∶1的直系同源关系。RT-PCR和基因芯片数据表明BmGSTz1在家蚕5龄第3天幼虫各组织中都有表达。序列和组织表达特征分析结果提示家蚕BmGSTz1可能具有MAAI活性,这将为进一步深入研究BmGSTz1基因的功能提供参考。
Glutathione S-transferases （GSTs） constitute a multifunctional superfamily in which Zeta class is widely distributed in animals,plants,and bacteria.In mammals,Zeta GSTs show maleylacetoacetate isomerase （MAAI） activity and participate in phenylalanine and tyrosine metabolism.In this study,expressed sequence tags （ESTs） were searched for the predicted GST gene from Bombyx mori,BmGSTz1.A contig containing 1 239 bp was assembled on the basis of ESTs of BmGSTz1,which extended into 3＇ and 5＇-UTR （untranslated region）.The contig of BmGSTz1 perfectly matched to the corresponding region of the silkworm genome sequence and had a poly （A） signal in its 3＇-UTR.BmGSTz1 was composed of 4 introns and 5 exons,and the boundary between exon and intron conformed to the canonical GT-AG rule.TA cloning verified that the coding sequence （CDS） was 648 bp in length and encoded 215 amino acids.The putative molecular weight and isoelectric point of BmGSTz1 were 24.8 kD and 8.06,respectively.BmGSTz1 had relatively high similarities with GSTz1 from insects and mammalians.Phylogenetic analysis showed that BmGSTz1,DmGSTz1,AgGSTz1,ApGSTz1,and TcGSTz1 might be 1：1：1：1：1 orthologues.The RT-PCR and microarray data indicated that BmGSTz1 was expressed in various tissues in Day-3 5th instar silkworm larvae.The results of sequence analysis and expression characterization suggest that BmGSTz1 might have the MAAI activity.The data presented in this study provide useful information for further studying the function of BmGSTz1.
出处
《昆虫学报》
CAS
CSCD
北大核心
2010年第10期1061-1068,共8页
Acta Entomologica Sinica
基金
中央高校基本科研业务费项目(CDJZR10290002)
国家高技术研究发展计划项目(2006AA10A117)
国家重点基础研究发展规划项目(2005CB121000)
关键词
家蚕
谷胱甘肽-S-转移酶
酪氨酸代谢
序列分析
CDNA克隆
表达特征
Bombyx mori
glutathione S-transferases
tyrosine metabolism
sequence analysis
cDNA cloning
expression characterization
