PrM- and cell-binding domains of the dengue virus E protein.
The E-prM proteins of flaviviruses are unusual complexes which play important roles in virus assembly and fusion modulation and in potential immunity-inducing vaccines. Despite their importance, little is known about the biogenesis and structural organization of E-prM complexes. Pulse-chase radiolabeling of dengue virus-infected Vero cells demonstrated a rapid interassociation of E and prM proteins, and sucrose gradient sedimentation analysis suggested that E-prM complexes progressed from simple heteromers to more densely sedimenting structures indicating increased multimerization. E-prM heteromers of even higher complexity were observed in virus particles, suggesting an intracellular assembly process which results in the networking of E-prM subunits into a lattice-like structure found in virus particles. Trypsin cleavage of E-prM-containing virus particles resulted in the release of a soluble 45-kDa fragment of the E protein which retained cell-binding activity. The results suggest that E-prM interactions in dengue virus particles are largely mediated by domains in the carboxy-terminal anchoring domain of E, while cell-binding activity is retained in a trypsin-releasable ectodomain of the E protein.
Wang
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Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada.
He
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Anderson
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D000818:Animals; D001665:Binding Sites; D002522:Chlorocebus aethiops; D003716:Dengue Virus / Q000502:physiology*; D011991:Receptors, Virus / Q000502:physiology*; D014357:Trypsin / Q000494:pharmacology; D014709:Vero Cells; D014764:Viral Proteins / Q000502:physiology*; D014771:Virion / Q000502:physiology