title: Mass spectrometric analysis of the glycosphingolipid-enriched microdomains of rat natural killer cells.
abstract: Glycosphingolipid-enriched microdomains (GEM) are membrane entities that concentrate glycosylphosphatiolylinositol(GPI)-anchored, acylated and membrane proteins important for immune receptor signaling. Using rat leukemic cell line RNK-16 we have initiated proteomic studies of microdomains in natural killer (NK) cells. Isolated plasma membranes were treated with Brij 58, or Nonidet-P40, or sodium carbonate. Extracts were separated by sucrose density gradient centrifugation into very light membrane, medium light membrane and heavy fractions, and a complete protein profile was analyzed by tandem mass spectrometry. Up to 250 proteins were unambiguously identified in each analyzed fraction. The first study of the proteome of NK cell GEM revealed several new aspects including identification of molecules not expected to be expressed in rat NK cells (e.g., NAP-22) or associated with GEM (e.g., NKR-P1, CD45, CD2). Moreover, it provided clear data consolidating controversial views concerning the occurrence of major histcompatibility complex glycoproteins and RT6.1/CD73/CD38 complex in NK cells. Our results also identified a large number of receptors as candidates for future functional studies.
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague 4, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Man
authors.forename: Petr
authors.initials: P
authors.lastname: Novák
authors.forename: Marek
authors.initials: M
authors.lastname: Cebecauer
authors.forename: Ondrej
authors.initials: O
authors.lastname: Horváth
authors.forename: Anna
authors.initials: A
authors.lastname: Fiserová
authors.forename: Vladimír
authors.initials: V
authors.lastname: Havlícek
authors.forename: Karel
authors.initials: K
authors.lastname: Bezouska
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D045744:Cell Line, Tumor; D002499:Centrifugation, Density Gradient; D006028:Glycosphingolipids / Q000737:chemistry* / Q000302:isolation & purification; D007694:Killer Cells, Natural / Q000737:chemistry*; D013058:Mass Spectrometry; D021962:Membrane Microdomains / Q000737:chemistry*; D040901:Proteomics; D051381:Rats
chemical_list: D006028:Glycosphingolipids