CAPPING OF MAMMALIAN U6 SMALL NUCLEAR-RNA INVITRO IS DIRECTED BY A CONSERVED STEM-LOOP AND AUAUAC SEQUENCE - CONVERSION OF A NONCAPPED RNA INTO A CAPPED RNA

被引:52
作者
SINGH, R [1 ]
GUPTA, S [1 ]
REDDY, R [1 ]
机构
[1] BAYLOR UNIV,DEPT PHARMACOL,1 BAYLOR PLAZA,HOUSTON,TX 77030
关键词
D O I
10.1128/MCB.10.3.939
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The cap structure of U6 small nuclear RNA (snRNA) is γ-monomethyl phosphate and is distinct from other known RNA cap structures (R. Singh and R. Reddy, Proc. Natl. Acad. Sci. USA 86:8280-8283, 1989). Here we show that the information for capping the U6 snRNA in vitro is within the initial 25 nucleotides of the U6 RNA. The capping determinant in mammalian U6 snRNA is a bipartite element - a phylogenetically conserved stem-loop structure and an AUAUAC sequence, or a part thereof, following this stem-loop. Wild-type capping efficiency was obtained when the AUAUAC motif immediately followed the stem-loop and when the γ-phosphate of the initiation nucleotide was in close proximity to the capping determinant. Incorporation of a synthetic stem-loop followed by an AUAUAC sequence is sufficient to covert a noncapped heterologous transcript into a capped transcript. Transcripts with the initial 32 nucleotides of Saccharomyces cerevisiae U6 snRNA are accurately capped in HeLa cell extract, indicating that capping machinery from HeLa cells can cap U6 snRNA from an evolutionarily distant eucaryote. The U6-snRNA-specific capping is unusual in that it is RNA sequence dependent, while the capping of mRNAs and other U snRNAs is tightly coupled to transcription and is independent of the RNA sequence.
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页码:939 / 946
页数:8
相关论文
共 36 条
[1]   5'-TERMINAL CAP STRUCTURE IN EUKARYOTIC MESSENGER RIBONUCLEIC-ACIDS [J].
BANERJEE, AK .
MICROBIOLOGICAL REVIEWS, 1980, 44 (02) :175-205
[2]   U1, U2, AND U4/U6 SMALL NUCLEAR RIBONUCLEOPROTEINS ARE REQUIRED FOR INVITRO SPLICING BUT NOT POLYADENYLATION [J].
BERGET, SM ;
ROBBERSON, BL .
CELL, 1986, 46 (05) :691-696
[3]   PRE-MESSENGER-RNA SPLICING INVITRO REQUIRES INTACT U4/U6 SMALL NUCLEAR RIBONUCLEOPROTEIN [J].
BLACK, DL ;
STEITZ, JA .
CELL, 1986, 46 (05) :697-704
[4]   SPLICEOSOMAL RNA U6 IS REMARKABLY CONSERVED FROM YEAST TO MAMMALS [J].
BROW, DA ;
GUTHRIE, C .
NATURE, 1988, 334 (6179) :213-218
[5]   RNA PROCESSING - SPLICING A SPLICEOSOMAL RNA [J].
BROW, DA ;
GUTHRIE, C .
NATURE, 1989, 337 (6202) :14-15
[6]   SNRNAS, SNRNPS, AND RNA PROCESSING [J].
BUSCH, H ;
REDDY, R ;
ROTHBLUM, L ;
CHOI, YC .
ANNUAL REVIEW OF BIOCHEMISTRY, 1982, 51 :617-654
[7]  
Dahlberg J. E., 1988, STRUCT FUNCT MAJOR M, P38, DOI [10.1007/978-3-642-73020-7_2, DOI 10.1007/978-3-642-73020-7_2]
[8]   UPSTREAM REGULATORY ELEMENTS ARE NECESSARY AND SUFFICIENT FOR TRANSCRIPTION OF A U6-RNA GENE BY RNA POLYMERASE-III [J].
DAS, G ;
HENNING, D ;
WRIGHT, D ;
REDDY, R .
EMBO JOURNAL, 1988, 7 (02) :503-512
[9]   ACCURATE TRANSCRIPTION INITIATION BY RNA POLYMERASE-II IN A SOLUBLE EXTRACT FROM ISOLATED MAMMALIAN NUCLEI [J].
DIGNAM, JD ;
LEBOVITZ, RM ;
ROEDER, RG .
NUCLEIC ACIDS RESEARCH, 1983, 11 (05) :1475-1489
[10]  
EPSTEIN P, 1980, J BIOL CHEM, V255, P8901