Effect of Signal Peptides on the Secretable Expression of Recombinant Chicken Igλ/GFP in COS7 Cells

ZHANG Hong1,2,WANG Jian1,LI Jiao2,YI Ming-lin2,HAN Hong-peng1,ZHANG Gai-ping2*(1.Henan Educational Institute,Zhengzhou 450003,China;2.Henan Key Laboratory of Animal Immunology,Zhengzhou 450002,China)

Signal peptide of chicken Igλ light chain;Signal peptide of murine plasmingen;Green fluroscent protein;Secretable expression

The signal peptides of chicken Igλ light chain and murine plasmingen were fused to the GFP N terminus using site-directed mutagenesis to construct the vectors with signal sequence,pEGFP-SPc and pEGFP-SPm.The chicken Igλ gene was inserted into the two vectors with signal sequence after double enzyme cutting.The results revealed that the vectors,pEGFP-SPc-λ and pEGFP-SPm-λ,with fusion gene of chicken Igλ and green fluroscent protein(GFP) were su-ccessfully constructed.The constructed recombinant vectors were transiently transfected into COS7 cells via lipofectamin.Secretable expression of Igλ/GFP in COS7 cells transfected with vector pEGFP-SPc-λ was observed under fluroscent microscope and in Western blotting.Expression of GFP fusion protein was located principally in plasma of COS7 cells transfected with pEGFP-SPm-λ vector.These findings suggest that signal peptides play a key role in secreted protein translocation.Signal peptide needs to be carefully chosen to guarantee the secretable expression of recombinant proteins.