Vesicle formation by self-assembly of membrane-bound matrix proteins into a fluidlike budding domain.
The shape of enveloped viruses depends critically on an internal protein matrix, yet it remains unclear how the matrix proteins control the geometry of the envelope membrane. We found that matrix proteins purified from Newcastle disease virus adsorb on a phospholipid bilayer and condense into fluidlike domains that cause membrane deformation and budding of spherical vesicles, as seen by fluorescent and electron microscopy. Measurements of the electrical admittance of the membrane resolved the gradual growth and rapid closure of a bud followed by its separation to form a free vesicle. The vesicle size distribution, confined by intrinsic curvature of budding domains, but broadened by their merger, matched the virus size distribution. Thus, matrix proteins implement domain-driven mechanism of budding, which suffices to control the shape of these proteolipid vesicles.
Shnyrova
Anna V
AV
Laboratory of Cellular and Molecular Biophysics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Ayllon
Juan
J
Mikhalyov
Ilya I
II
Villar
Enrique
E
Zimmerberg
Joshua
J
Frolov
Vadim A
VA
D002784:Cholesterol / Q000737:chemistry; D004983:Ethanolamines / Q000737:chemistry; D005456:Fluorescent Dyes; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D008051:Lipid Bilayers / Q000737:chemistry; D008854:Microscopy, Electron; D009522:Newcastle disease virus / Q000737:chemistry / Q000502:physiology; D018408:Patch-Clamp Techniques; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D010767:Phosphorylcholine / Q000737:chemistry; D017434:Protein Structure, Tertiary; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013816:Thermodynamics; D053835:Unilamellar Liposomes / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000378:metabolism; D014763:Viral Matrix Proteins / Q000096:biosynthesis* / Q000737:chemistry
D004983:Ethanolamines; D005456:Fluorescent Dyes; D006023:Glycoproteins; D008051:Lipid Bilayers; D010743:Phospholipids; D053835:Unilamellar Liposomes; D014759:Viral Envelope Proteins; D014763:Viral Matrix Proteins; C023587:protein M (glycoprotein); D010767:Phosphorylcholine; C005448:phosphorylethanolamine; D002784:Cholesterol