IDENTIFICATION AND MOLECULAR CHARACTERIZATION OF TWO SERINE PROTEASES AND THEIR POTENTIAL INVOLVEMENT IN PROPHENOLOXIDASE ACTIVATION IN Plutella xylostella.
The proteolytic activation of prophenoloxidase (proPO) is a humoral defense mechanism in insects and crustaceans. Phenoloxidase (PO) is produced as an inactive precursor namely, proPO and is activated via specific proteolytic cleavage by proPO-activating proteinase. The current research reports two novel serine proteinase genes (PxSP1-768 bp and PxSP2-816 bp) from Plutella xylostella, encoding 255 and 271 amino acid residues, respectively. Tissue distribution analyses by semiquantitative reverse transcription-PCR (RT-PCR) revealed the resultant genes to be primarily expressed in the hemocytes, while quantitative-RT-PCR (qRT-PCR) assay showed that transcription level of PxSP1 and PxSP2 increased significantly after injection of the fungal pathogen Beauveria bassiana. Purified recombinant fusion proteins of PxSP2 and PxSP1 were injected to New Zealand white rabbits and polyclonal antibodies were generated with the titers of 1:12,800. After silencing the expression of PxSP2 by RNAi, the PO activity decreased significantly. The results show that PxSP2 is involved in prophenoloxidase activation in P. xylostella.
Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, South China Agricultural University, Guangzhou, P. R. China.
Gang
G
Gao
Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, South China Agricultural University, Guangzhou, P. R. China.
Xiao-Xia
XX
Xu
Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, South China Agricultural University, Guangzhou, P. R. China.
Jing
J
Yu
Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, South China Agricultural University, Guangzhou, P. R. China.
Lin-Miao
LM
Li
Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, South China Agricultural University, Guangzhou, P. R. China.
Wen-Yan
WY
Ju
Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, South China Agricultural University, Guangzhou, P. R. China.
Feng-Liang
FL
Jin
Department of Entomology, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan, Pakistan.
Shoaib
S
Freed
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D052982:Beauveria / Q000502:physiology; D004156:Catechol Oxidase / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004792:Enzyme Precursors / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D007814:Larva; D009036:Moths / Q000201:enzymology* / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D010063:Ovum / Q000254:growth & development / Q000378:metabolism; D010802:Phylogeny; D011679:Pupa; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D057057:Serine Proteases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D018076:DNA, Complementary; D004792:Enzyme Precursors; D019476:Insect Proteins; D012333:RNA, Messenger; C038451:pro-phenoloxidase; D004156:Catechol Oxidase; D057057:Serine Proteases
Plutella xylostella; RNA interference; entomopathogenic fungi; phenoloxidase cascade; serine protease