1. Identification and characterization of a 38 kDa glycoprotein functionally associated with mating activity of Paramecium primaurelia.
- Author
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Ognibene M, Della Giovampaola C, Trielli F, Focarelli R, Rosati F, and Umberta Delmonte Corrado M
- Subjects
- Animals, Antibodies, Protozoan metabolism, Antibodies, Protozoan pharmacology, Cell Membrane chemistry, Cilia chemistry, Glycoproteins isolation & purification, Life Cycle Stages physiology, Paramecium chemistry, Plant Lectins metabolism, Protozoan Proteins isolation & purification, Reproduction physiology, Ribosome Inactivating Proteins metabolism, Tritium metabolism, Glycoproteins metabolism, Paramecium physiology, Protozoan Proteins metabolism
- Abstract
In Paramecium primaurelia mating interactions take place immediately after mixing mating-competent cells of opposite mating types. The cells clump in clusters (mating reaction) and then separate in pairs. Previous results have shown that sialic acid-containing glycoconjugates are present on the cell surface and are involved in mating-cell pairing. In order to identify the sialic acid-containing glycoprotein(s), we first metabolically radiolabelled non-mating-competent cells with D-[6-(3)H]galactose, and then analyzed the radiolabelled proteins by anion exchange chromatography. We characterized a 38 kDa (gp38) sialic acid-containing glycoprotein and raised the corresponding polyclonal antibody by means of which we localized the antigen at the level of the oral region of non-mating-competent cells and on the ciliary surface of mating-competent cells. Immunoblot analysis of the ciliary protein fraction showed that the anti-gp38 serum interacted with a 38 kDa protein in both mating types I and II cells. We also demonstrated the functional activity of gp38 in the mating reaction by means of anti-gp38 antibody competition assays.
- Published
- 2008
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