Biomaterial Database

Compartmentalization of phosphatidylinositol 4,5-bisphosphate in low-density membrane domains in the absence of caveolin. 1998

Y Liu, and L Casey, and L J Pike

Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.

In cells that exhibit caveolae, the hormone-sensitive pool of PtdIns 4,5-P2 is localized in a low density, caveolin-enriched membrane fraction (1). Neuro 2a cells do not express caveolin. Nonetheless, the PtdIns 4,5-P2 in these cells is compartmentalized in a low density, detergent-insoluble domain that also contains other signaling-related molecules. Compartmentalization of PtdIns 4,5-P2 was observed regardless of whether Triton X-100-containing or detergent-free methods were used to prepare the membranes. However, the partitioning of receptor tyrosine kinases and GPI-anchored proteins into the low density domains was dependent upon the method of membrane preparation. Treatment of Neuro 2a cells with cyclodextrin delocalized the PtdIns 4,5-P2 and inhibited hormone-stimulated PtdIns turnover. These results suggest that compartmentalization of PtdIns 4,5-P2 does not require caveolin but is necessary for the proper functioning of phosphoinositide-based signaling.

UI	MeSH Term	Description	Entries
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D002451	Cell Compartmentation	A partitioning within cells due to the selectively permeable membranes which enclose each of the separate parts, e.g., mitochondria, lysosomes, etc.	Cell Compartmentations,Compartmentation, Cell,Compartmentations, Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D003505	Cyclodextrins	A homologous group of cyclic GLUCANS consisting of alpha-1,4 bound glucose units obtained by the action of cyclodextrin glucanotransferase on starch or similar substrates. The enzyme is produced by certain species of Bacillus. Cyclodextrins form inclusion complexes with a wide variety of substances.	Cycloamylose,Cyclodextrin,Cyclodextrin Derivatives,Cyclomaltooligosaccharides,Derivatives, Cyclodextrin
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D015153	Blotting, Western	Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.	Immunoblotting, Western,Western Blotting,Western Immunoblotting,Blot, Western,Immunoblot, Western,Western Blot,Western Immunoblot,Blots, Western,Blottings, Western,Immunoblots, Western,Immunoblottings, Western,Western Blots,Western Blottings,Western Immunoblots,Western Immunoblottings
D051242	Caveolin 1	A tyrosine phosphoprotein that plays an essential role in CAVEOLAE formation. It binds CHOLESTEROL and is involved in LIPIDS transport, membrane traffic, and SIGNAL TRANSDUCTION.	Caveolin-1,VIP21 Protein,Vesicular Integral Membrane Protein 21 kDa,alpha-Caveolin,beta-Caveolin,alpha Caveolin,beta Caveolin
D017830	Octoxynol	Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.	Octylphenoxypolyethoxyethanols,Octoxinol,Octoxinols,Octoxynol-9,Octoxynols,Octylphenoxy Polyethoxyethanol,Triton X-100,Triton X-305,Triton X-45,Octoxynol 9,Polyethoxyethanol, Octylphenoxy,Triton X 100,Triton X 305,Triton X 45,Triton X100,Triton X305,Triton X45
D019269	Phosphatidylinositol 4,5-Diphosphate	A phosphoinositide present in all eukaryotic cells, particularly in the plasma membrane. It is the major substrate for receptor-stimulated phosphoinositidase C, with the consequent formation of inositol 1,4,5-triphosphate and diacylglycerol, and probably also for receptor-stimulated inositol phospholipid 3-kinase. (Kendrew, The Encyclopedia of Molecular Biology, 1994)	PtdInsP2,Phosphatidylinositol 4,5-Biphosphate,Phosphatidylinositol Phosphate, PtdIns(4,5)P2,Phosphatidylinositol-4,5-Biphosphate,PtIns 4,5-P2,PtdIns(4,5)P2,PtdInsP,4,5-Biphosphate, Phosphatidylinositol,4,5-Diphosphate, Phosphatidylinositol,Phosphatidylinositol 4,5 Biphosphate,Phosphatidylinositol 4,5 Diphosphate