Constitutive formation of caveolae in a bacterium.
Caveolin plays an essential role in the formation of characteristic surface pits, caveolae, which cover the surface of many animal cells. The fundamental principles of caveola formation are only slowly emerging. Here we show that caveolin expression in a prokaryotic host lacking any intracellular membrane system drives the formation of cytoplasmic vesicles containing polymeric caveolin. Vesicle formation is induced by expression of wild-type caveolins, but not caveolin mutants defective in caveola formation in mammalian systems. In addition, cryoelectron tomography shows that the induced membrane domains are equivalent in size and caveolin density to native caveolae and reveals a possible polyhedral arrangement of caveolin oligomers. The caveolin-induced vesicles or heterologous caveolae (h-caveolae) form by budding in from the cytoplasmic membrane, generating a membrane domain with distinct lipid composition. Periplasmic solutes are encapsulated in the budding h-caveola, and purified h-caveolae can be tailored to be targeted to specific cells of interest.
The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland 4072, Australia. piers.walser@nhsbt.nhs.uk
Piers J
PJ
Walser
Nicholas
N
Ariotti
Mark
M
Howes
Charles
C
Ferguson
Richard
R
Webb
Dominik
D
Schwudke
Natalya
N
Leneva
Kwang-Jin
KJ
Cho
Leanne
L
Cooper
James
J
Rae
Matthias
M
Floetenmeyer
Viola M J
VM
Oorschot
Ulf
U
Skoglund
Kai
K
Simons
John F
JF
Hancock
Robert G
RG
Parton
D000818:Animals; D021941:Caveolae / Q000378:metabolism* / Q000648:ultrastructure*; D022461:Caveolins / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D004926:Escherichia coli; D006801:Humans; D008322:Mammals / Q000378:metabolism*
D022461:Caveolins