|ZHU, YU - Zhejiang University|
|YE, XIN-HAI - South China Agricultural University|
|LIU, YANG - Zhejiang University|
|YAN, ZHI-CHAO - Zhejiang University|
|YE, GONG-YIN - Zhejiang University|
|FANG, QI - Zhejiang University|
Submitted to: Toxins
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2015
Publication Date: 11/30/2015
Citation: Zhu, Y., Ye, X., Liu, Y., Yan, Z., Ye, G., Stanley, D.W., Fang, Q. 2015. A Venom Gland Extracellular Chitin-Binding-Like Protein from Pupal Endoparasitoid Wasps, Pteromalus Puparum, Selectively Binds Chitin. Toxins. 2015, 7(12), 5098-5113.
Interpretive Summary: Application of classical insecticides has introduced severe problems in agricultural sustainability. The concept of biological control of insects is a potentially powerful alternative to classical insecticides. Biological control is based on the idea that direct application of insect-specific parasites can reduce pest insect populations and the economic damage due to pest insects. The problem, however, is the efficiency of these parasites in biological control programs is limited by insect immune defense reactions to challenge. One approach to improving the efficiency of biocontrol agents would be to somehow disable insect immune reactions to parasitic infections. This approach motivates our work on understanding the interactions between insect parasites and their host insects. Here we report discovery of a protein in the venom of an insect parasite that may serve to protect the parasite. This discovery will be of direct help to scientists working to understand insect parasites and ultimately support agricultural sustainability by improving biological control technologies.
Technical Abstract: Chitin-binding proteins (CBPs) existed in various species and involved in different biology processes. In the present study, we cloned a full length cDNA of chitin-binding protein-like (PpCBP-like) from Pteromalus puparum, a pupal endoparasitoid of Pieris rapae. PpCBP-like encoded a 96 putative amino acid protein, including a secretory signal peptide and a chitin binding peritrophin-A domain. Phylogenetic analysis of chitin binding domains (CBDs) of cuticle proteins and peritrophic matrix proteins in different insects revealed that CBD of PpCBP-like clustered with CBD of Nasonia vitripennis CBP-like and CBD of Fenneropenaeus merguiensis SOP (shrimp ovarian peritrophin). With qPCR, western blot and immunocytochemistry analyses, all results indicated that PpCBP-like is specifically expressed in venom apparatus of P. puparum. A time-course analysis showed that the expression of PpCBP-like was peaked at day 4 post-eclosion. The chitin- and cellulose-binding assay showed that the recombinant PpCBP-like can bind to chitin, but not to cellulose in vitro. These results suggested that PpCBP-like may serve as a structure component of the venom reservoir to protect it from the bioactive proteins produced by venom gland. Both identification and characterization of PpCBP-like in this study provide valuable information for further investigation of the physiological function of this venom protein.