The membrane-anchor of Paramecium temperature-specific surface antigens is a glycosylinositol phospholipid

• Published in: Biochemical and biophysical research communications Vol. 147; no. 3; pp. 1219 - 1225
• Main Authors: Capdeville, Yvonne, Cardoso de Almeida, M. Lucia, Deregnaucourt, Christiane
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 30.09.1987; Elsevier
• Subjects: Acylation; Animals; antigens; Antigens, Surface - analysis; Applied sciences; cell surface; Exact sciences and technology; Glycolipids - metabolism; Membrane Lipids - metabolism; Membrane Proteins - metabolism; membranes; Myristic Acid; Myristic Acids - metabolism; Other techniques and industries; Paramecium - analysis; Paramecium - immunology; Paramecium - metabolism; Paramecium primaurelia; Phosphatidylinositols - metabolism; Temperature; Type C Phospholipases - metabolism; sSAg; CRD; PIPLC; SAg; CRG; VSG; mSAg
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(87)80200-0

The temperature-specific G surface antigen of Paramecium primaurelia strain 156 was biosynthetically labeled by [ 3H]myristic acid in its membrane-bound form, but not in its soluble form. It could be cleaved by a phosphatidylinositol-specific phospholipase C from Trypanosoma brucei or from Bacillus cereus which released its soluble form with the unmasking of a particular glycosidic immunodeterminant called the crossreacting determinant. The Paramecium enzyme, capable of converting its membrane-bound form into the soluble one, was inhibited by a sulphydril reagent in the same way as the trypanosomal lipase. From this evidence we propose that the Paramecium temperature-specific surface antigens are anchored in the plasma membrane via a glycophospholipid, and that an endogenous phospholipase C may be involved in the antigenic variation process.