De novo formation of caveolae in lymphocytes by expression of VIP21-caveolin.
Caveolae are plasma membrane invaginations, which have been implicated in endothelial transcytosis, endocytosis, potocytosis, and signal transduction. In addition to their well-defined morphology, caveolae are characterized by the presence of an integral membrane protein termed VIP21-caveolin. We have recently observed that lymphocytes have no detectable VIP21-caveolin and lack plasma membrane invaginations resembling caveolae. Here we transiently express VIP21-caveolin in a lymphocyte cell line using the Semliki Forest virus expression system and show de novo formation of plasma membrane invaginations containing VIP21-caveolin. These invaginations appear homogeneous in size and morphologically indistinguishable from caveolae of nonlymphoid cells. Moreover, the glycosylphosphatidylinositol-anchored protein. Thy1, patched by antibodies, redistributes to the newly formed caveolae. Our results show that VIP21-caveolin is a key structural component required for caveolar biogenesis.
Fra
A M
AM
European Molecular Biology Laboratory, Heidelberg, Germany.
Williamson
E
E
Simons
K
K
Parton
R G
RG
D000818:Animals; D001692:Biological Transport; D015153:Blotting, Western; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D051242:Caveolin 1; D022461:Caveolins; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure*; D006224:Cricetinae; D006825:Hybridomas / Q000502:physiology / Q000648:ultrastructure; D008214:Lymphocytes / Q000378:metabolism / Q000648:ultrastructure*; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D016253:Microscopy, Immunoelectron; D010316:Particle Size; D011994:Recombinant Proteins / Q000096:biosynthesis; D012672:Semliki forest virus / Q000235:genetics; D015398:Signal Transduction
D002352:Carrier Proteins; D051242:Caveolin 1; D022461:Caveolins; D008565:Membrane Proteins; D011994:Recombinant Proteins