Hemagglutinin of influenza virus partitions into the nonraft domain of model membranes.
The HA of influenza virus is a paradigm for a transmembrane protein thought to be associated with membrane-rafts, liquid-ordered like nanodomains of the plasma membrane enriched in cholesterol, glycosphingolipids, and saturated phospholipids. Due to their submicron size in cells, rafts can not be visualized directly and raft-association of HA was hitherto analyzed by indirect methods. In this study, we have used GUVs and GPMVs, showing liquid disordered and liquid ordered domains, to directly visualize partition of HA by fluorescence microscopy. We show that HA is exclusively (GUVs) or predominantly (GPMVs) present in the liquid disordered domain, regardless of whether authentic HA or domains containing its raft targeting signals were reconstituted into model membranes. The preferential partition of HA into ld domains and the difference between lo partition in GUV and GPMV are discussed with respect to differences in packaging of lipids in membranes of model systems and living cells suggesting that physical properties of lipid domains in biological membranes are tightly regulated by protein-lipid interactions.
Nikolaus
Jörg
J
Department of Biology, Molecular Biophysics, Humboldt University Berlin, Berlin, Germany.
Scolari
Silvia
S
Bayraktarov
Elisa
E
Jungnick
Nadine
N
Engel
Stephanie
S
Pia Plazzo
Anna
A
Stöckl
Martin
M
Volkmer
Rudolf
R
Veit
Michael
M
Herrmann
Andreas
A
D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000378:metabolism*; D008055:Lipids / Q000737:chemistry; D021962:Membrane Microdomains / Q000378:metabolism*; D008567:Membranes, Artificial; D008954:Models, Biological; D010455:Peptides / Q000737:chemistry; D017434:Protein Structure, Tertiary; D013050:Spectrometry, Fluorescence; D053835:Unilamellar Liposomes / Q000378:metabolism
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D008055:Lipids; D008567:Membranes, Artificial; D010455:Peptides; D053835:Unilamellar Liposomes