Association of small nuclear RNA with HnRNA isolated from nuclear RNP complexes carrying HnRNA

Flytzanis, Constantin N.; Alonso, Ángel; Louis, Christos; Krieg, Liselotte; Sékeris, Constantin E.

doi:10.1016/0014-5793(78)81094-1

Cited by 65 publications

(16 citation statements)

References 21 publications

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“…Thus, it is very likely that the snRNA is hydrogen bonded to hnRNA. A similar conclusion has been drawn recently from hybridization experiments [32]. Moreover, Jellinek and Leinwand [33] could demonstrate that low-molecular-weight RNAs are hydrogen bonded to nuclear poly(A)-containing RNA of Chinese hamster ovary cells even after phenol extraction.…”

Section: Sodium C L O T / C~c ; I~l S U L F E I~e ~~O L~~c I T~isupporting

confidence: 82%

The Effect of Urea on the Structure of Nuclear Ribonucleoprotein Particles from Rat Liver

Northemann

Klump

Heinrich

1979

European Journal of Biochemistry

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Ribonucleoprotein particles were isolated in the presence of cytosolic RNase inhibitor from rat liver nuclei and exposed to increasing concentrations of urea. The average sedimentation coefficient of 90 S in a sucrose gradient decreased slightly with urea concentrations of up to 2 M. At 5 M urea the particles sedimented at about 20 S. The protein-to-RNA ratio decreased from 4 to 1.4 after treatment with 5 M urea. The proteins which are preferentially detached from the ribonucleoprotein complex are in the molecular weight range of 30000-45000. In addition, small nuclear RNAs (snRNA) were dissociated from the ribonucleoprotein particles by high urea concentrations (> 2 M). From the fact that snRNAs are dissociated from the ribonucleoprotein complex by high urea concentrations and not dissociated by high NaCl concentrations even after extensive proteolytic digestion, it is concluded that hydrogen bonds are involved in their binding to heterogeneous nuclear RNA (hnRNA).The change in the RNA conformation after addition of increasing concentrations of urea was studied by circular dichroism measurements of ribonucleoprotein particles and protein-free particle RNA. In the presence of 5 M urea the molar ellipticities at 264 nm decreased from 15

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Section: Sodium C L O T / C~c ; I~l S U L F E I~e ~~O L~~c I T~isupporting

confidence: 82%

The Effect of Urea on the Structure of Nuclear Ribonucleoprotein Particles from Rat Liver

Northemann

Klump

Heinrich

1979

European Journal of Biochemistry

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“…Four of these small RNA (4.5SI, U1A, U2 and U3B RNA) isolated from rat Novikoff Hepatoma cells were sequenced by Busch and coworkers (5)(6)(7)(8). The interest for the small nuclear RNA was renewed by the finding that they may be hydrogen-bonded to premessenger RNA (9,10) and that they were present in the ribonucleoproteins containing the premessenger RNA (11)(12)(13)(14) which are assumed to be the site of splicing. Therefore, it was proposed that the small RNA might insure the proper alignment of premessenger RNA sequences for splicing (15)(16)(17).…”

Section: Introductionmentioning

confidence: 99%

Nucleotide sequences of nuclear U1A RNAs from chicken, rat and man

et al. 1980

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SUMMARYThe methods of enzymatic and chemical treatment of end-labeled RNA were applied to the determination of the nucleotide sequence of chicken and man UlA RNA and to the reexamination of that of rat UlA RNA. The chemical method allowed the easy demonstration of the cap structure. All three RNA were 165 nucleotide long. Two hitherto non described modified pyrimidines were detected close to the 5' end. Only 9 base substitutions were observed from chicken to man indicating a high degree of conservation of UlA RNA through evolution. INTRODUCTIONMetabolically stable low molecular weight RNA were found in the nuclei of a variety of cell types (1-4). Four of these small RNA (4.5SI, U1A, U2 and U3B RNA) isolated from rat Novikoff Hepatoma cells were sequenced by Busch and coworkers (5-8). The interest for the small nuclear RNA was renewed by the finding that they may be hydrogen-bonded to premessenger RNA (9, 10) and that they were present in the ribonucleoproteins containing the premessenger RNA (11-14) which are assumed to be the site of splicing. Therefore, it was proposed that the small RNA might insure the proper alignment of premessenger RNA sequences for splicing (15)(16)(17). This idea was reinforced by the observation of at certain complementari:ty between a single sequence a the 5' end of UlA RNA and a consensus of the intron sequences adjacent to the splice point in premessenger RNA. As premessenger RNA from various animal species were used for the establishment of the consensus sequence and as only the published sequence of rat UlA RNA was available (6), the model implied a high conservation of the primary structure of UlA RNA through evolution (16). This prompted us to determine the complete nucleotide sequence of UlA RNA from 2 other animal species, chicken

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“…It is present in large ribonucleoprotein particles that are loosely associated with euchromatin (29,30). U-1 RNA and heterogeneous nuclear RNA (hnRNA) can be co-isolated from these complexes and are dissociated by 70% formamide, which suggests that U-1 RNA is bound to hnRNA by short regions of base pairing (31). U-1 is the most abundant snRNA found in cells whose mRNAs are generated by RNA splicing, including human, mouse, chicken (12,32), and rat (33) cells.…”

Section: '-(Exon)-a-g/g-t-a-a-g-t-a-(intron) -T-t-t-t-y-t-t-t-t-t-t-mentioning

confidence: 99%

A mechanism for RNA splicing.

Rogers¹,

Wall²

1980

Proc. Natl. Acad. Sci. U.S.A.

475

162

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ABSrRACT The most abundant of the stable small nuclear RNAs of eukaryotic cells, U-1 small nuclear RNA, is exactly complementary to the consensus sequences at RNA splice sites.We propose that this RNA is the recognition component of the nuclear RNA splicing enzyme and forms base pairs with both ends of an intron so as to align them for cutting and splicing.Intramolecular RNA splicing, first discovered for the adenovirus-specific RNA (1-3), occurs in the expression of numerous eukaryotic genes (4). At present there are three known classes of DNA sequences at splice sites, found in genes for a chloroplast tRNA (5), yeast tRNAs (6), and vertebrate mRNAs (7-9). Each class has distinctive sequence characteristics. For the splice sites of vertebrate genes, comparisons of a limited set of sequences (7,8) showed that introns were flanked in every case by 5'-/ G-T-(intron)-A-G/-3'. Subsequent sequences have borne this out (9) and have shown that the 5' ("upstream") and 3' ("downstream") ends of introns have approximately the following consensus or "optimal" sequences: 5'-(exon)-A-G/G-T-A-A-G-T-A-(intron) -T-T-T-T-Y-T-T-T-T-T-T-C-T-T-N-C-A-G/G-(exon)-3'.The upstream and downstream splice sites in nuclear RNA molecules presumably must be brought together for RNA splicing to occur. This could be achieved by intramolecular base pairing, but no appropriate complementary structures have been found reproducibly in the vicinity of splice sites (10). We propose an alternative mechanism in which upstream and downstream splicing sites form base pairs with another RNA molecule which could be a structural component of the splicing enzyme(s). There may be an example comparable to this proposed splicing system in RNase P of Escherichia coli, which is a site-specific RNase with an essential RNA component (I1).THE MODEL We considered that such an effector RNA might be found among the discrete; stable, small nuclear RNAs (snRNAs) that are ubiquitous in eukaryotic cells (12). Sequences have been reported for several of these (13-17). When we compared the sequence of U-i snRNA from rat hepatoma (13) with sequences of the optimal splice site (Fig. 1), we discovered that the first 10 nucleotides after the U-1 RNA cap are perfectly complementary to the 9 nucleotides of the optimal upstream site and to the tetranucleotide C-A-G/G from the optimal downstream site. The next 11 nucleotides of U-I are purine-rich and can be aligned with the pyrimidine-rich segment of the downstream site. This striking complementarity with splicing sites is not found in any of the other snRNAs now sequenced, which are U-2 (14), 4.5S (15), and adenovirus VA-I RNAs (16,17). We therefore propose that U-1 snRNA in the RNA splicing complex forms base pairs with both ends of an intron in a large nuclear RNA molecule as shown in Fig. 2, bringing

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Association of small nuclear RNA with HnRNA isolated from nuclear RNP complexes carrying HnRNA

Cited by 65 publications

References 21 publications

The Effect of Urea on the Structure of Nuclear Ribonucleoprotein Particles from Rat Liver

The Effect of Urea on the Structure of Nuclear Ribonucleoprotein Particles from Rat Liver

Nucleotide sequences of nuclear U1A RNAs from chicken, rat and man

A mechanism for RNA splicing.

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