Biomaterial Database

Defective glycosyl phosphatidylinositol biosynthesis in extracts of three Thy-1 negative lymphoma cell mutants. 1991

V L Stevens, and C R Raetz

Department of Biochemistry, Merck Sharp and Dohme Research Laboratories, Rahway, New Jersey 07065.

The glycosyl phosphatidylinositol (GPI) anchors that attach certain proteins to membranes are preassembled by sequential addition of glycan components to phosphatidylinositol (PI) before being transferred to nascent polypeptide. A cell-free system consisting of trypanosome membranes has been reported to catalyze GPI biosynthesis (Masterson, W. J., Doering, T. L., Hart, G. W., and Englund, P. T. (1989) Cell 56, 793-800; Menon, A. K., Schwarz, R. T., Mayor, S., and Cross, G. A. M. (1990) J. Biol. Chem. 265, 9033-9042). We now describe conditions for studying the initial steps of GPI biosynthesis in extracts of murine lymphoma cells. Two chloroform-soluble products, tentatively identified as [6-3H]GlcNAc-PI and [6-3H]GlcN-PI were generated during incubations of EL4 cell lysates with UDP-[6-3H]GlcNAc. The involvement of PI in the reaction was established by the sensitivity of the products to hydrolysis by PI-specific phospholipase C and the finding that the addition of exogenous PI to the incubation stimulated the reaction. The minor, more polar product was sensitive to nitrous acid cleavage and was converted to the major product, as judged by TLC, after treatment with acetic anhydride. The glycolipids generated in lymphoma extracts appeared to be the same as the products produced in parallel incubations with trypanosome membranes. Analysis of available lymphoma mutants deficient in Thy-1 surface expression revealed that extracts of the class A, C, and H mutants are completely defective in synthesizing GlcNAc-PI and GlcN-PI.

UI	MeSH Term	Description	Entries
D008223	Lymphoma	A general term for various neoplastic diseases of the lymphoid tissue.	Germinoblastoma,Lymphoma, Malignant,Reticulolymphosarcoma,Sarcoma, Germinoblastic,Germinoblastic Sarcoma,Germinoblastic Sarcomas,Germinoblastomas,Lymphomas,Lymphomas, Malignant,Malignant Lymphoma,Malignant Lymphomas,Reticulolymphosarcomas,Sarcomas, Germinoblastic
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010716	Phosphatidylinositols	Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.	Inositide Phospholipid,Inositol Phosphoglyceride,Inositol Phosphoglycerides,Inositol Phospholipid,Phosphoinositide,Phosphoinositides,PtdIns,Inositide Phospholipids,Inositol Phospholipids,Phosphatidyl Inositol,Phosphatidylinositol,Inositol, Phosphatidyl,Phosphoglyceride, Inositol,Phosphoglycerides, Inositol,Phospholipid, Inositide,Phospholipid, Inositol,Phospholipids, Inositide,Phospholipids, Inositol
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D002474	Cell-Free System	A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)	Cellfree System,Cell Free System,Cell-Free Systems,Cellfree Systems,System, Cell-Free,System, Cellfree,Systems, Cell-Free,Systems, Cellfree
D002855	Chromatography, Thin Layer	Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Thin-Layer,Thin Layer Chromatography,Chromatographies, Thin Layer,Chromatographies, Thin-Layer,Thin Layer Chromatographies,Thin-Layer Chromatographies,Thin-Layer Chromatography
D006017	Glycolipids	Any compound containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol (see GLYCERIDES), a sphingoid, a ceramide (CERAMIDES) (N-acylsphingoid) or a prenyl phosphate. (From IUPAC's webpage)	Glycolipid
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
D001345	Autoradiography	The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)	Radioautography
D014346	Trypanosoma brucei brucei	A hemoflagellate subspecies of parasitic protozoa that causes nagana in domestic and game animals in Africa. It apparently does not infect humans. It is transmitted by bites of tsetse flies (Glossina).	Trypanosoma brucei,Trypanosoma brucei bruceus,Trypanosoma bruceus,brucei brucei, Trypanosoma,brucei, Trypanosoma brucei,bruceus, Trypanosoma,bruceus, Trypanosoma brucei