Sequence analysis and expression characteristics of defensin-2 protein from Apis mellifera
[Objective]The purpose of the study was to conduct the protein sequence analysis and expression charac-teristics studies of Defensin-2(Def-2)protein of Apis mellifera,in order to provide a theoretical references for exploring the immune defense mechanism,development and metabolic pathway of defensin gene in A.melliferia.[Method]Bioin-formatics analysis websites and software were used to predict and analyze Def-2 protein,while the gene relative expres-sion levels of A.mellifera at different developmental stages(larva stage,pupa stage and 1,5,10,15,20,25 and 30 d adult stage worker bee)were analyzed by real-time fluorescence quantitative PCR.[Result]The Def-2 gene of A.mellifera en-coded 104 amino acids residues with a relative molecular weight of 11858.90 Da and an isoelectric point(pI)of 8.54,identifying it as an amphipathic,unstable protein.This protein had a signal peptide of 21 amino acids at its N-terminus and had one transmembrane domain.The subcellular location was primarily in the endoplasmic reticulum,vacu-oles,and Golgi body.There were no glycosylation sites and only 15 phosphorylation sites.The secondary structure of this protein was dominated by random coil structure(54.81%),with large distribution of extended chain(28.85%)and a few α-helix(16.35%).The protein sequence was highly conserved and interacted genetically with proteins such as Def-1,GB44032-PA,Dl-2 and Imd,and contained defense protein-like domain(DEFL),which adopted a structure characterized by a cysteine-stabilized α/β scaffold.The phylogenetic relationship showed close similarity to A.florea.The expression level of Def-2 gene of A.mellifera varied at different developmental stages and increased with age,the relative expression of 30 d was significantly higher than the other days(P<0.05).[Conclusion]Def-2 protein of A.mellifera is an amphipa-thic unstable protein,which is involved in intercellular signal transmission and maintains normal cell morphology.The pro-tein sequence is highly conserved,with the closest phylogenetic relationship to A.florea.The gene is expressed in high abundance at 30 d of adult A.mellifera,suggesting that it may regulate immune gene transport and affect the immune recog-nition process of A.mellifera.
万方数据
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