Heterogeneous nuclear RNA secondary structure: oligo (U) sequences base-paired with poly (A) and their possible role as binding sites for heterogeneous nuclear RNA-specific proteins.
HeLa cell heterogeneous nuclear RNA derived from high-molecular-weight nuclear ribonucleoprotein (RNP) particles contains oligo(U) sequences of 15-50 nucleotides base-paired with poly(A). These duplexes are resistant to pancreatic RNase at 0.5 M NaCl in native RNP, remain so after chemical deproteinization of the RNP digests, and then copurify with poly(A) on oligo(dT)-cellulose chromatography. Oligo(dT)-cellulose binding capacity of the oligo(U)-poly(A) duplexes is abolished by prior titration of the nonduplex poly(A) regions with excess poly(U). The oligo(dT)-purified fraction is 97.5 mole % A + U and the [3H]uridine-labeled component is resistant to redigestion by pancreatic RNase at 0.5 M NaCl but not at 0.01 M NaCl. After thermal denaturation, the [3H]uridine-labeled chains become RNase-sensitive at 0.5 M NaCl. Electrophoresis of [3H]adenosine- or [3H]uridine-labeled material in polyacrylamide gels containing 99% formamide confirms that the oligo(U) sequences are not covalently linked to poly(A). Controls establish that the A-U duplexes are not formed artifactually during isolation of heterogeneous nuclear RNP or subsequent fractionation. The oligo(U)-poly(A) duplexes appear to be associated with protein in native heterogeneous nuclear RNP, as reflected by the differential pancreatic RNase sensitivity of the duplexed oligo(U) in RNP (resistant) and RNA (sensitive), measured at physiological ionic strength.
D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D006367:HeLa Cells / Q000378:metabolism; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D009698:Nucleoproteins / Q000378:metabolism; D011061:Poly A / Q000032:analysis; D011072:Poly U / Q000032:analysis; D012334:RNA, Neoplasm / Q000378:metabolism; D012260:Ribonucleases; D012261:Ribonucleoproteins / Q000378:metabolism
D009698:Nucleoproteins; D012334:RNA, Neoplasm; D012261:Ribonucleoproteins; D011061:Poly A; D011072:Poly U; D012260:Ribonucleases
J Biol Chem. 1960 Aug;235:2393-8
13798248
Biochemistry. 1976 Oct 19;15(21):4643-9
974081
J Biol Chem. 1976 Oct 10;251(19):5888-94
972146
Science. 1971 Oct 29;174(4008):507-10
5110429
J Biol Chem. 1973 Feb 25;248(4):1472-6
4346958
Proc Natl Acad Sci U S A. 1975 Jan;72(1):301-5
1054507
Proc Natl Acad Sci U S A. 1974 Jan;71(1):200-4
4544010
Proc Natl Acad Sci U S A. 1972 Dec;69(12):3684-8
4509331
Proc Natl Acad Sci U S A. 1972 Sep;69(9):2537-41
4506771
Biochemistry. 1972 Feb 29;11(5):792-8
4536742
J Mol Biol. 1974 Feb 25;83(2):163-83
4821869
Biochim Biophys Acta. 1973 Jun 8;312(1):152-64
4737856
Biochemistry. 1973 Jun 5;12(12):2324-30
4710583
J Mol Biol. 1966 Sep;20(2):359-89
5339332
Eur J Biochem. 1976 Jan 15;61(2):563-72
813998
Proc Natl Acad Sci U S A. 1971 Jun;68(6):1336-40
5288383
J Mol Biol. 1975 Jun 25;95(2):227-38
1185781
J Mol Biol. 1975 Aug 15;96(3):353-65
1165583