The carboxy-terminal 18 amino acids of the measles virus hemagglutinin are essential for its biological function.
The hemagglutinin (HA) glycoprotein encoded by measles virus (MV) is a type II integral membrane protein that is expressed at the infected cell surface. Genes encoding wild-type MV HA as well as two mutant HA proteins shortened at their carboxy-termini by either 18 (HA delta 18O) or 223 (HA delta 223) amino acids were constructed and studied in a transient expression system in COS cells. Under nonreducing conditions, assembly of HA delta 18 into homodimers was diminished while HA delta 223 remained in a monomeric form. Hemadsorption assays revealed that neither mutant was functional at the cell surface. These studies show that the carboxy-terminal ectodomain of the HA protein is essential to its proper folding and assembly into homodimers while its carboxy-terminal 18 amino acids are essential for the hemadsorption (receptor-binding) function of the protein.
Blain
F
F
Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada.
Liston
P
P
Briedis
D J
DJ
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D002918:Chymotrypsin; D004912:Erythrocytes / Q000276:immunology; D006384:Hemagglutination; D006389:Hemagglutinins, Viral / Q000096:biosynthesis* / Q000737:chemistry* / Q000276:immunology; D007668:Kidney; D007700:Kinetics; D046911:Macromolecular Substances; D008459:Measles virus / Q000276:immunology*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010449:Peptide Mapping; D017510:Protein Folding; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000276:immunology; D017384:Sequence Deletion; D014162:Transfection; D014709:Vero Cells
D006389:Hemagglutinins, Viral; D046911:Macromolecular Substances; D011994:Recombinant Proteins; C032397:hemagglutinin protein G, measles virus; D002918:Chymotrypsin