Separation of Caveolae from Associated Microdomains of GPI-Anchored Proteins

• Published in: Science (American Association for the Advancement of Science) 1995-09, Vol.269 (5229), p.1435-1439
• Main Authors: Schnitzer, Jan E., McIntosh, Deirdre P., Dvorak, Ann M., Liu, Jun, Oh, Phil
• Format: Article
• Language: English
• Subjects: 5'-Nucleotidase - analysis; Animals; Antibodies; Biological and medical sciences; Caveolae; Caveolin 1; Caveolins; Cell Fractionation; Cell Membrane - chemistry; Cell Membrane - ultrastructure; Cell membranes; Cell physiology; Cellular biology; Cellular signal transduction; Coatings; Colloids; Detergents; Endothelial cells; Endothelium, Vascular - ultrastructure; Fundamental and applied biological sciences. Psychology; Glycolipids; Glycosylphosphatidylinositols - analysis; GPI linked proteins; Lungs; Membrane and intracellular transports; Membrane Proteins - analysis; Microscopy, Immunoelectron; Molecular and cellular biology; P branes; Plasma membranes; Proteins; Rats; Receptors, Cell Surface - analysis; Receptors, Urokinase Plasminogen Activator; Rodents; Signal Transduction; Silicon Dioxide; Solubility; String theory
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.7660128

In situ coating of the surface of endothelial cells in rat lung with cationic colloidal silica particles was used to separate caveolae from detergent-insoluble membranes rich in glycosyl phosphatidylinositol (GPI)-anchored proteins but devoid of caveolin. Immunogold electron microscopy showed that ganglioside G$_{M1}$-enriched caveolae associated with an annular plasmalemmal domain enriched in GPI-anchored proteins. The purified caveolae contained molecular components required for regulated transport, including various lipid-anchored signaling molecules. Such specialized distinct microdomains may exist separately or together in the plasma membrane to organize signaling molecules and to process surface-bound ligands differentially.