Poly (A)-rich ribonucleoprotein complexes from HeLa cell messenger RNA.
Polyribosomal messenger RNA from HeLa cells contain 3'-OH-terminal polyadenylate sequences approximately 133 nucleotides in length (weight average). When analyzed at the ribonucleoprotein level of organization these poly(A)-rich sequences are found to contain tightly bound proteins. These proteins remain associated with the poly(A)-rich RNA during affinity chromatography of RNase A and T1-digested polyribosomes on poly(U)-Sepharose in 0.5 M NaCl, and co-elute from the column with the RNA at 50% formamide. Controls establish that the co-purification of the proteins with poly(A) on poly(U)-Sepharose requires the molecular integrity of the poly(A). Polyacrylamide gel electrophoresis resolves the poly(A)-specific proteins into two components of 74,000 and 62,000 molecular weight. The larger protein is the same size as that previously reported to be associated with poly(A)-rich sequences in HeLa heterogeneous nuclear RNA (Kish, V.M., and Pederson, T. (1975), J. Mol. Biol. 95, 227-238). It is concluded that both HeLa nuclear and polyribosomal poly(A) sequences have a protein (62,000 molecular weight) associated with poly(A) appears to be confined only to messenger RNA.
D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells / Q000378:metabolism*; D008970:Molecular Weight; D009698:Nucleoproteins / Q000378:metabolism; D010455:Peptides / Q000032:analysis; D011061:Poly A / Q000032:analysis*; D011132:Polyribosomes / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D012260:Ribonucleases; D012261:Ribonucleoproteins / Q000378:metabolism
D009698:Nucleoproteins; D010455:Peptides; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D012261:Ribonucleoproteins; D011061:Poly A; D012260:Ribonucleases