Stable trimerization of recombinant rabies virus glycoprotein ectodomain is required for interaction with the p75NTR receptor.
Native rabies virus glycoprotein (RVGvir) is a trimeric, membrane-anchored protein that has been shown to interact with the p75NTR neurotrophin receptor. In order to determine if the RVG trimeric oligomerization state is required for its binding with p75NTR, different soluble recombinant molecules containing the entire RVG ectodomain (RVGect) were expressed alone or fused at its C terminus to the trimerization domain of the bacteriophage T4 fibritin, termed 'foldon'. The oligomerization status of recombinant RVG was investigated using sedimentation in sucrose gradient and p75NTR binding assays. It was found that, in the absence of the fibritin foldon, recombinant RVGect forms unstable trimers that dissociate into monomers in a concentration-dependent manner. C-terminal fusion with the foldon induces stable RVG trimerization, which is concentration-independent. Furthermore, the fibritin foldon maintains the native antigenic structure of the carboxy part of RVGect. Cell binding experiments showed that RVG trimerization is required for efficient interaction with p75NTR. However, the exact mode of trimerization appears unimportant, as trimeric recombinant RVGect (fused to the fibritin foldon) and RVGvir both recognize p75NTR with similar nanomolar affinities, as shown by surface plasmon resonance experiments. Altogether, these results show that the C-terminal fusion of the RVG ectodomain with the fibritin foldon is a powerful way to obtain a recombinant trimeric native-like structure of the p75NTR binding domain of RVG.
Sissoëff
Ludmilla
L
Laboratoire de Virologie Moléculaire et Structurale, UMR 2472 CNRS-INRA, 91198 Gif-sur-Yvette, France.
Mousli
Mohamed
M
Laboratoire de Virologie Moléculaire et Structurale, UMR 2472 CNRS-INRA, 91198 Gif-sur-Yvette, France.
England
Patrick
P
Plateforme de Biophysique des Macromolécules et de leurs Interactions, Institut Pasteur, 75015 Paris, France.
Tuffereau
Christine
C
Laboratoire de Virologie Moléculaire et Structurale, UMR 2472 CNRS-INRA, 91198 Gif-sur-Yvette, France.
D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016367:Baculoviridae / Q000235:genetics / Q000378:metabolism; D019556:COS Cells; D002460:Cell Line; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D002522:Chlorocebus aethiops; D006224:Cricetinae; D019281:Dimerization; D006023:Glycoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012995:Solubility; D018411:Spodoptera; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D000956:Antigens, Viral; D006023:Glycoproteins; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C057839:fibritin protein, Enterobacteria phage T4; C064951:glycoprotein G, Rabies virus