Sequestration of GPI-anchored proteins in caveolae triggered by cross-linking.
Glycosyl-phosphatidylinositol (GPI)-anchored proteins have been reported to reside in clusters collected over small membrane invaginations called caveolae. The detection of different GPI-anchored proteins with fluorescently labeled monoclonal antibodies showed that these proteins are not constitutively concentrated in caveolae; they enter these structures independently after cross-linking with polyclonal secondary antibodies. Analysis of the cell surface distribution of the GPI-anchored folate receptor by electron microscopy confirms these observations. Thus, multimerization of GPI-anchored proteins regulates their sequestration in caveolae, but in the absence of agents that promote clustering they are diffusely distributed over the plasma membrane.
Mayor
S
S
Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
Rothberg
K G
KG
Maxfield
F R
FR
D016475:3T3 Cells; D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D018958:CD55 Antigens; D002352:Carrier Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D051242:Caveolin 1; D022461:Caveolins; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis; D051379:Mice; D008854:Microscopy, Electron; D011956:Receptors, Cell Surface; D018800:Thy-1 Antigens; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000954:Antigens, Surface; D018958:CD55 Antigens; D002352:Carrier Proteins; D051242:Caveolin 1; D022461:Caveolins; D058973:Folate Receptors, GPI-Anchored; D017261:Glycosylphosphatidylinositols; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D018800:Thy-1 Antigens; D005492:Folic Acid