title: Biochemical analysis suggests distinct functional roles for the BLAST-1 and BLAST-2 antigens.
abstract: The biochemical processing of the BLAST-1 and BLAST-2 activation antigens has been studied. Both are glycoproteins that derive from different precursors of the same apparent m.w. on SDS-PAGE. BLAST-1 is synthesized as a 43,000 m.w. light chain in association with a second heavier chain of 55,000 m.w. The light chain acquires sialylated O-linked glycans and is stably expressed at the cell surface with a half-life of 14 hr. BLAST-2 is also synthesized as a 43,000 m.w. precursor, but it acquires only unsialylated N-linked glycans. The mature glycoprotein is only expressed briefly at the cell surface (half-life of 1 to 2 hr), and is then shed into the culture supernatant as a soluble 33,000 m.w. derivative. The different fates of these molecules, one stably expressed at the cell surface and one shed, suggest disparate roles for these two antigens in B cell activation.
authors.forename: D A
authors.initials: DA
authors.lastname: Thorley-Lawson
authors.forename: S L
authors.initials: SL
authors.lastname: Swendeman
authors.forename: C M
authors.initials: CM
authors.lastname: Edson
mesh_terms: D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification*; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D008970:Molecular Weight; D011233:Precipitin Tests; D011498:Protein Precursors / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification; D011499:Protein Processing, Post-Translational
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D006023:Glycoproteins; D011498:Protein Precursors