Biochemical analysis of the secreted and virion glycoproteins of Ebola virus.
The glycoproteins expressed by a Zaire species of Ebola virus were analyzed for cleavage, oligomerization, and other structural properties to better define their functions. The 50- to 70-kDa secreted and 150-kDa virion/structural glycoproteins (SGP and GP, respectively), which share the 295 N-terminal residues, are cleaved near the N terminus by signalase. A second cleavage event, occurring in GP at a multibasic site (RRTRR downward arrow) that is likely mediated by furin, results in two glycoproteins (GP1 and GP2) linked by disulfide bonding. This furin cleavage site is present in the same position in the GPs of all Ebola viruses (R[R/K]X[R/K]R downward arrow), and one is predicted for Marburg viruses (R[R/K]KR downward arrow), although in a different location. Based on the results of cross-linking studies, we were able to determine that Ebola virion peplomers are composed of trimers of GP1-GP2 heterodimers and that aspects of their structure are similar to those of retroviruses, paramyxoviruses, and influenza viruses. We also determined that SGP is secreted from infected cells almost exclusively in the form of a homodimer that is joined by disulfide bonding.
Sanchez
A
A
Special Pathogens Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. ans1@cdc.gov
Yang
Z Y
ZY
Xu
L
L
Nabel
G J
GJ
Crews
T
T
Peters
C J
CJ
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D002522:Chlorocebus aethiops; D029043:Ebolavirus / Q000737:chemistry* / Q000276:immunology; D006023:Glycoproteins / Q000032:analysis* / Q000276:immunology; D006801:Humans; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000276:immunology; D014709:Vero Cells; D014763:Viral Matrix Proteins / Q000032:analysis* / Q000276:immunology; D014764:Viral Proteins; D014771:Virion
D000914:Antibodies, Viral; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D014763:Viral Matrix Proteins; D014764:Viral Proteins; C110613:secreted glycoprotein, Ebola virus; C110614:transmembrane glycoprotein, Ebola virus