Alterations to influenza virus hemagglutinin cytoplasmic tail modulate virus infectivity.

摘要: Abstract The influenza virus hemagglutinin (HA) contains a cytoplasmic domain that consists of 10 to 11 amino acids, which five residues have sequence identity for 13 HA subtypes. To investigate properties these conserved residues, oligonucleotide-directed mutagenesis was performed, using an cDNA A/Udorn/72 (H3N2) substitute the cysteine with other delete three C-terminal or remove entire domain. The altered HAs were expressed in eukaryotic cells, and rates intracellular transport examined. It found substitution either residue within did not affect rate transport, whereas deletion resulted delayed cell surface expression. All biologically active hemadsorption fusion assays. whether wild-type tails could complement temperature-sensitive transport-defective mutant A/WSN/33 ts61S, cDNAs by transient expression system released assayed plaque analysis. release approximately 10(3) PFU per ml. Antibody neutralization complemented indicated infectivity due incorporation H3 into ts61S virions. Sucrose density gradient analysis virions showed each mutants incorporated particles. Virions containing be infectious. However, no detected from had deletions their domains. Possible roles forming protein-protein interactions involvement initiation infection process cells are discussed.