桃小食心虫CsasCSP14的基因克隆及分子对接
Cloning and molecular docking of the Carposina sasakii chemosensory protein gene, CsasCSP14
刘孝贺 孙丽娜 佟兆国 张怀江 闫文涛1 岳 强1 仇贵生
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DOI:10.7679/j.issn.2095-1353.2021.065
作者单位:中国农业科学院果树研究所,兴城 125100;中国农业科学院植物保护研究所,北京 100193; 西昌学院农业科学学院,西昌 615013
中文关键词:桃小食心虫;CsasCSP14;基因克隆;分子对接;荧光定量
英文关键词:Carposina Sasakii; CsasCSP14; gene cloning; molecular docking; real-time qPCR
中文摘要:
【目的】 本研究旨在获得桃小食心虫Carposina sasakii Matsumura CsasCSP14基因序列,分析其在雌雄不同组织中的表达差异,并与寄主挥发物进行分子对接,为该基因的功能研究提供参考。【方法】 以桃小食心虫全组织cDNA为模板,通过PCR技术扩增克隆获得CsasCSP14 cDNA序列全长;利用生信分析软件分析其编码蛋白的理化性质和结构特征;通过荧光定量PCR技术分析CsasCSP14在桃小食心虫雌雄成虫不同组织(触角、头、胸、腹、足和翅)中的表达情况;使用Modeller(version 9.19)构建CsasCSP14蛋白的三维结构模型;运用Autodock 4.2将CsasCSP14与32种苹果挥发物和2种性信息素分子进行分子对接。【结果】 克隆获得了桃小食心虫化学感受蛋白基因CsasCSP14的cDNA序列,其开放阅读框(Open reading frame,ORF)长度为369 bp,编码122个氨基酸,预测其蛋白分子量为14.13 ku,理论等电点为5.20,有17个氨基酸残基组成的信号肽序列,且18-122位氨基酸之间存在昆虫化学感受蛋白家族保守结构域;含有4个保守的半胱氨酸位点。CsasCSP14具有6个α螺旋;氨基酸同源比对结果显示,CsasCSP14与玉米螟Pyrausta nubilalis OfurCSP5的氨基酸序列一致性最高,达到79.01%。荧光定量PCR结果显示,CsasCSP14在雌雄成虫的触角、头、胸、腹、足和翅中均有表达,但是其表达丰度有差异,在雌雄成虫触角中的表达量最高。通过Modeller软件搜索CsasCSP14三维结构的模板,得到与沙漠蝗Schistocerca gregaria CSPsg4序列相似性为65.7%。因此以CSPsg4为模板成功构建CsasCSP14三维结构。分子对接结果表明CsasCSP14与2-己烯醛、桃醛、醋酸丁酯、庚醛、异戊醛和法尼烯气味分子结合能比较低,并且Leu-22、Phe-29、Phe-42和Ile-46 4个疏水性氨基酸残基在结合过程中发挥了关键作用。【结论】 本研究为进一步了解桃小食心虫CsasCSP14基因功能和利用化学生态的方法防控该虫提供了前期理论基础。
英文摘要:
[Objectives] To clone
the cDNA sequence of the Carposina sasakii CSP14 gene, CsasCSP14, determine its expression
profiles in different tissues of both sexes, and its molecular docking with
host volatiles, and thereby lay a foundation for the future study of the
physiological function of this gene. [Methods] The full-length cDNA sequence of CsasCSP14 was cloned from body tissues of C. sasakii by PCR. The expression levels
of CsasCSP14 mRNA in different
tissues (antennae, head, thorax, abdomen, legs and wings) were detected by
real-time PCR. Modeller software (version-9.19) was used to build a
three-dimensional model of CsasCSP14 and Autodock 4.2 was then used to dock
this model to 32 apple plant volatiles and 2 sex pheromones. [Results] The open reading frame (ORF) of the
full-length cDNA sequence of CsasCSP14 obtained using real-time
PCR was 369 bp long, encoding a protein of 122 aa with an estimated molecular
weight 14.13 ku and a pI of 5.20. The encoded protein has a signal peptide, no
transmembrane structure, a CSP superfamily domain between residues 18-122 and
contains four conserved cysteins and 6 α-helixes. The results of amino acid sequence
alignment indicate that CsasCSP14 is homologous to OfurCSP13 with 86% amino
acid sequence identify. Furthermore, the results of real-time PCR show that CsasCSP14 transcripts are differentially expressed in the antennae, head, thorax,
abdomen, legs and wings of male and female adults. The highest expression of CsasCSP14 was in the antennae of adult males and females. Modeller was used to
compare the sequence of CsasCSP14 with those of previously characterized
proteins in the Protein Data Bank (PDB). CsasCSP14 shares 65.03% similarity
with S. gregaria CSPsg4; the 3D structure of CSPsg4 was used as the
template for the 3D structure of CsasCSP14. [Conclusion] The results of molecular docking
simulation indicate that 2-Hexenal, Undecanolactone, Butyl-acetate, Heptanal,
3-Methylbutanal and Farnesene have relatively low binding energies with
CsasCSP14. However, the hydrophobic amino acid resides Leu-22, Phe-29, Phe-42
and Ile-46, interact with all CsasCSP14 ligands. These results provide a
theoretical basis for further research on the binding of CsasCSP14 to host
plant volatiles, and thereby facilitate the development of new methods of
controlling C. sasakii.