title: Isolation and cell-free translation of messenger ribonucleic acids specifying thymus-leukemia antigens.
abstract: Messenger ribonucleic acid (mRNA) for thymus-leukemia antigens, membrane-associated glycoproteins of murine leukemia cells, was obtained from polysomes of murine leukemia cells forming thymus-leukemia antigens. Polysomes forming thymus-leukemia antigens were recovered by immunoprecipitation using alloantibodies specific for the 1,2,3 determinants of the thymus-leukemia antigen complex before they were extracted with phenol-detergent. Poly(adenylic acid)-containing RNA [poly(A)-RNA] was fractionated by oligo[deoxythymidylate] [oligo(dT)]-cellulose chromatography. The mRNA obtained had a sedimentation coefficient of approximately 17 S in agreement with the predicted size necessary for forming proteins specifying thymus-leukemia antigens. In a wheat germ system, the polypeptides formed upon addition of mRNA for thymus-leukemia antigens consisted of a major product with a molecular weight of 42,000. It was larger than the nonglycosylated heavy chain molecule of 40,000 daltons formed by the cells themselves. On the cell surface thymus-leukemia antigens exist as glycosylated molecules of 47,000 daltons associated with a light-chain equivalent to beta 2-microglobulin. Molecules of 40,000 daltons were isolated from the cells cultured in the presence of tunicamycin, an inhibitor of de novo glycosylation, and by treating thymus-leukemia heavy chains with endo-beta-N-acetylglucosaminidase H.
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D002462:Cell Membrane / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis*; D007106:Immune Sera; D007118:Immunoassay; D007942:Leukemia, Experimental / Q000378:metabolism*; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000096:biosynthesis*; D051379:Mice; D008970:Molecular Weight; D010944:Plants / Q000378:metabolism; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism*; D013950:Thymus Gland / Q000378:metabolism; D014908:Triticum / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; D006023:Glycoproteins; D007106:Immune Sera; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D012333:RNA, Messenger; C028388:thymus-leukemia antigens