Preliminary Analysis Of AGO2 And AGO3 From Schistosoma Japonicum Argonaute Protein(AGO) Family

Schistosomiasis is a chronic debilitating disease that currently affects in human and livestock worldwide. Prevention for Schistosomiasis is still the most urgen work for us to do which is also the most important thing that World Health Organization has considered. Praziquantel must be a good choice for us to do with Schistosomiasis.But there can be drug resistance after too much and offen use of this drug. What is more important, Praziquantel can do nothing with repeated infection.It's a great cost in order to develop a new drug to deal with Schistosomiasis.People is always disappointed that new drugs was always bring a low effect. Nowdays many scientists pay more attention to vaccine.they expect to find a better way to treat Schistosomiasis. Research about investigating the protective immunity of the vaccine against schistosomiasis has take good progress in the past years.But it is still a long way to go to reach the goal of controling Schistosomiasis. We still have much to do with vaccine.The first most important thing is to keep on finding a vaccine candidate molecule of Schistosoma japonicum.The present study was intended to obtain two full-length cDNA encoding Argonaute protein (SjAGO) in Schistosoma japonicum and subsequently express the recombinant protein in E.coli BL21. Two cDNA fragment encoding Argonaute was harvested as applying the RNA template isolated from Schistosoma japomnicum by using 5'RACE and 3'RACE technique. Upon bioinformatical extension, a full-length cDNA encoding Argonaute protein from Schistosoma japonicum was obtained including a complete Open Reading Frame. Bioinformatical analysis indicated that both of the SjAGO contain PAZ and PIWI domain, which is a typical character for Argonaute protein family in other organism. The cDNA fragment encoding SjAGO2 and SjAGO3 were further cloned into pET-28a(+) vectors and the recombinant plasmids were transfected into E.coli BL21 cell.The recombinant protein was purified by using NTA column. Kunming mice were immunized with the purified protein to raise polyclonal antibodies. The transcript profile of SjAGO from 7d,14d,21d,32d and 42d schisotomes was determined by using Real-time RT-PCR and showed that the predominantly transcript of SjAGO3 was observed at adult schistosoma.We got nearly the same result that the predominantly expression of the protein SjAGO2 and SjAGO3 wre detected at adult schistosoma when we analysis the Argonaute protein express by western blot in different stage of schistosoma. In conclusion:we cloned two full-length cDNA encoding Argonaute protein from Schistosoma japonicum and also carried out some preliminary studies. Our results presented here provide foundational information for further investigating Argonaute's roles in schistosoma development.