Schistosoma japonicum proteins that interact with the gynecophoral canal protein identified using a yeast two-hybrid system

The large amount of schistosome eggs produced by mature female worms not only induce major pathological damage to the host but also lead to the transmission of schistosomiasis. Mature female schistosome worms need constant pairing contact with a male partner as male signaling is indispensable to female growth, development, and reproduction. The gynecophoral canal protein (GCP), a cell-surface glycoprotein, plays a potential role in the interaction between males and females and in stimulating female development and maturation. In this study, a yeast two-hybrid cDNA library of Schistosoma japonicum (Sj) parasites 18 days post-infection (dpi) was constructed; the Sjgcp gene was inserted into a pGBKT7-BD bait plasmid and used as a bait protein to screen for its molecular interactions using a yeast mating procedure. Twenty-four prey proteins that interacted with the SjGCP were selected after excluding false positives; the interactions between S.japonicum lethal giant larvae (SjLGL) and SjGCP, S.japonicum type V collagen (SjColV) and SjGCP, were verified by co-immunoprecipitation. The RNA interference against SjGCP, SjColV and SjGCP + SjColV led to severe underdevelopment of tegument in male worms and vitelline globules in female worms as well as reduced reproductive capacity of the females. Collectively, SjGCP and its interacting proteins may play pivotal roles in growth and development. The findings also suggested that SjGCP and its interacting protein partners might represent new candidate targets for drug development against schistosomiasis.

LvCSN5 is involved in WSSV infection via interaction with wsv006

As an extremely virulent pathogen, white spot syndrome virus (WSSV) greatly threatens shrimp aquaculture worldwide. The interaction between virus and host is important for viral infection. In the present study, a yeast two-hybrid (Y2H) library was constructed to clarify the functions of wsv006, and the interaction between wsv006 and shrimp Litopenaeus vannamei (L. vannamei) was analyzed. Furthermore, we explored the role of the wsv006-interacting molecule L. vannamei COP9 constitutive photomorphogenic-like protein subunit 5 (LvCSN5) in WSSV infection. Y2H assay showed that wsv006 interacted with LvCSN5, and co-immunoprecipitation (Co-IP) assay confirmed such interaction. Multiple alignments of amino acid sequences with other species revealed that the LvCSN5 had high identity with Penaeusmonodon CSN5 (PmCSN5). LvCSN5 was mainly expressed in intestine, eye and hepatopancreas. In addition, the relative expression of LvCSN5 was significantly up-regulated both in intestine and hepatopancreas following the WSSV challenge. Besides, the relative expressions of IE1 and VP28, as well as the viral copy numbers were significantly increased in the LvCSN5-silenced shrimp. Our findings suggested that LvCSN5 was involved in WSSV infection by interacting with wsv006.

Screening of binding proteins that interact with Chinese sacbrood virus VP3 capsid protein in Apis cerana larvae cDNA library by the yeast two-hybrid method

Chinese sacbrood virus (CSBV) causes larval death and apiary collapse of Apis cerana. VP3 is a capsid protein of CSBV but its function is poorly understood. To determine the function of VP3 and screen for novel binding proteins that interact with VP3, we conducted yeast two-hybrid screening, glutathione S-transferase pull-down, and co-immunoprecipitation assays. Galectin (GAL) is a protein involved in immune regulation and host-pathogen interactions. The yeast two-hybrid screen implicated GAL as a major VP3-binding candidate. The assays showed that the VP3 interacted with GAL. Identification of these cellular targets and clarifying their contributions to the host-pathogen interaction may be useful for the development of novel therapeutic and prevention strategies against CSBV infection.