Influenza virus assembly and lipid raft microdomains: a role for the cytoplasmic tails of the spike glycoproteins

J Zhang, A Pekosz, RA Lamb - Journal of virology, 2000 - Am Soc Microbiol
J Zhang, A Pekosz, RA Lamb
Journal of virology, 2000Am Soc Microbiol
Influenza viruses encoding hemagglutinin (HA) and neuraminidase (NA) glycoproteins with
deletions in one or both cytoplasmic tails (HAt− or NAt−) have a reduced association with
detergent-insoluble glycolipids (DIGs). Mutations which eliminated various combinations of
the three palmitoylation sites in HA exhibited reduced amounts of DIG-associated HA in
virus-infected cells. The influenza virus matrix (M1) protein was also found to be associated
with DIGs, but this association was decreased in cells infected with HAt− or NAt− virus …
Abstract
Influenza viruses encoding hemagglutinin (HA) and neuraminidase (NA) glycoproteins with deletions in one or both cytoplasmic tails (HAt− or NAt−) have a reduced association with detergent-insoluble glycolipids (DIGs). Mutations which eliminated various combinations of the three palmitoylation sites in HA exhibited reduced amounts of DIG-associated HA in virus-infected cells. The influenza virus matrix (M1) protein was also found to be associated with DIGs, but this association was decreased in cells infected with HAt− or NAt− virus. Regardless of the amount of DIG-associated protein, the HA and NA glycoproteins were targeted primarily to the apical surface of virus-infected, polarized cells. The uncoupling of DIG association and apical transport was augmented by the observation that the influenza A virus M2 protein as well as the influenza C virus HA-esterase-fusion glycoprotein were not associated with DIGs but were apically targeted. The reduced DIG association of HAt− and NAt− is an intrinsic property of the glycoproteins, as similar reductions in DIG association were observed when the proteins were expressed from cDNA. Examination of purified virions indicated reduced amounts of DIG-associated lipids in the envelope of HAt− and NAt− viruses. The data indicate that deletion of both the HA and NA cytoplasmic tails results in reduced DIG association and changes in both virus polypeptide and lipid composition.
American Society for Microbiology