Comparison of methylated sequences in messenger RNA and heterogeneous nuclear RNA from mouse L cells

Schibler, Ueli; Kelley, Dawn E.; Perry, Robert P.

doi:10.1016/0022-2836(77)90110-3

Cited by 225 publications

(160 citation statements)

References 23 publications

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“…In no case did we detect both the 1.1-and 1.3-kb transcripts in the same cell type, nor did we observe mRNA containing combinations of the tissuespecific exons, i.e., fibroblast with skeletal muscle. These results clearly indicate that utilization of tissue-specific methylation (11,23,84,98); and (iii) trans-acting factors such as proteins and small nuclear RNAs (6,47,66,76). At the nucleotide sequence level, all introns within genes encoding proteins have a well-defined consensus sequence at the 5' and 3' boundaries (7,65,86).…”

Section: Beta-tropomyosin and Fibroblast Tropomyosin 1 Cdnas Wementioning

confidence: 79%

Nonmuscle and muscle tropomyosin isoforms are expressed from a single gene by alternative RNA splicing and polyadenylation.

Helfman¹,

Cheley²,

Kuismanen³

et al. 1986

Mol. Cell. Biol.

175

122

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The molecular basis for the expression of rat embryonic fibroblast tropomyosin 1 and skeletal muscle beta-tropomyosin was determined. cDNA clones encoding these tropomyosin isoforms exhibit complete identity except for two carboxy-proximal regions (amino acids 189 to 213 and 258 to 284) and different 3'-untranslated sequences. The isoform-specific regions delineate the troponin T-binding domains of skeletal muscle tropomyosin. Analysis of genomic clones indicates that there are two separate loci in the rat genome that contain sequences complementary to these mRNAs. One locus is a pseudogene. The other locus contains a single gene made up of 11 exons and spans approximately 10 kilobases. Sequences common to all mRNAs were found in exons 1 through 5 (amino acids 1 to 188) and exons 8 and 9 (amino acids 214 to 257). Exons 6 and 11 are specific for fibroblast mRNA (amino acids 189 to 213 and 258 to 284, respectively), while exons 7 and 10 are specific for skeletal muscle mRNA (amino acids 189 to 213 and 258 to 284, respectively). In addition, exons 10 and 11 each contain the entire 3'-untranslated sequences of the respective mRNAs including the polyadenylation site. Although the gene is also expressed in smooth muscle (stomach, uterus, and vas deferens), only the fibroblast-type splice products can be detected in these tissues. S1 and primer extension analyses indicate that all mRNAs expressed from this gene are transcribed from a single promoter. The promoter was found to contain G-C-rich sequences, a TATA-like sequence TTTTA, no identifiable CCAAT box, and two putative Sp1-binding sites.

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Section: Beta-tropomyosin and Fibroblast Tropomyosin 1 Cdnas Wementioning

confidence: 79%

Nonmuscle and muscle tropomyosin isoforms are expressed from a single gene by alternative RNA splicing and polyadenylation.

Helfman¹,

Cheley²,

Kuismanen³

et al. 1986

Mol. Cell. Biol.

175

122

View full text Add to dashboard Cite

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“…This element usually consists of a cytidine residue at the cap site followed by an uninterrupted sequence of 7-13 pyrimidine nucleotides (16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Indeed, about half of all mRNAs with a 5'-terminal cytidine residue may be rp mRNAs (26,27).…”

mentioning

confidence: 99%

Oligopyrimidine tract at the 5' end of mammalian ribosomal protein mRNAs is required for their translational control.

Levy

Avni

Hariharan

et al. 1991

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

316

233

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Mammalian ribosomal protein (rp) mRNAs are subject to translational control, as illustrated by their selective release from polyribosomes in growth-arrested cells and their underrepresentation in polysomes in normally growing cells. In the present experiments, we have emined whether the translational control of rp mRNAs is attributable to the distinctive features of their 5' untranslated region, in particular to the oligopyrimidine tract adjacent to the cap structure. Murine lymphosarcoma cells were transfected with chimeric genes consisting of selected regions of rp mRNA fused to non-rp mRNA segments, and the translational efficiency of the resulting chimeric mRNAs was assessed in cells that either were growing normally or were growth-arrested by glucocorticoid treatment. We observed that translational control of rpL32 mRNA was abolished when its 5' untranslated region was replaced by that of .8-actin. At the same time, human growth hormone (hGH) mRNA acquired the typical behavior of rp mRNAs when it was preceded by the first 61 nucleotides of rpL30 mRNA or the first 29 nucleotides of rpS16 mRNA. Moreover, the translational control of rpSl6-hGH mRNA was abolished by the substitution of purines into the pyrimidine tract or by shortening it from eight to six residues with a concomitant cytidine -* uridine change at the 5' terminus.These results indicate that the 5'-terminal pyrimidine tract plays a critical role in the translational control mechanism. Possible factors that might interact with this translational cis regulatory element are discussed.Control at the translational level plays a dominant role in the regulated expression of eukaryotic ribosomal protein (rp) genes under a variety of conditions (1-3). These include: early development of Dictyostelium discoideum (4), Drosophila melanogaster (5)

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“…Secondary effects of the drugs have not been ruled out. Furthermore, the requirement for internal methylation in mRNA is not absolute, as mature messages without any detectable m6A residues do exist, including globin and histone mRNAs (24,27).In all cases characterized to date, m6A occurs only in the sequences Gm6AC and Am6AC (7,12,31,38). Preliminary localization studies with specific RNAs have determined that the distribution of m6A within a molecule is nonrandom.…”

mentioning

confidence: 99%

“…In all cases characterized to date, m6A occurs only in the sequences Gm6AC and Am6AC (7,12,31,38). Preliminary localization studies with specific RNAs have determined that the distribution of m6A within a molecule is nonrandom.…”

mentioning

confidence: 99%

Precise localization of m6A in Rous sarcoma virus RNA reveals clustering of methylation sites: implications for RNA processing.

Kane¹,

Beemon²

1985

Mol. Cell. Biol.

169

306

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N6-methyladenosine (m6A) residues are present as internal base modifications in most higher eucaryotic mRNAs; however, the biological function of this modification is not known. We describe a method for localizing and quantitating m6A within a large RNA In addition to having 5'-methylated cap structures, many eucaryotic mRNAs contain internal methylated bases. N6-methyladenosine (m6A), the major form of modified nucleoside, has been detected in most higher eucaryotic cell mRNAs, in viral mRNAs, and in the virion RNA of retroviruses (2). Methylation of internal adenosines occurs in the nucleus very rapidly after synthesis of the heterogeneous nuclear RNA precursor to mRNA and before the RNA is spliced (9, 28). While the function of this internal methylation is not known, several observations suggest a significant role for m6A in RNA metabolism.Some implications for the function of internal base modifications come from methylation inhibition studies, using either cycloleucine or S-tubercidinylhomocysteine to block internal methylation of RNA. These experiments suggest an involvement of m6A in RNA processing events or in the transport of mRNA from the nucleus to the cytoplasm (6, 13, 35). It is not clear from these studies, however, that the effect of the inhibitors is directly related to the methylation state of the mRNA being examined. Secondary effects of the drugs have not been ruled out. Furthermore, the requirement for internal methylation in mRNA is not absolute, as mature messages without any detectable m6A residues do exist, including globin and histone mRNAs (24,27).In all cases characterized to date, m6A occurs only in the sequences Gm6AC and Am6AC (7,12,31,38). Preliminary localization studies with specific RNAs have determined that the distribution of m6A within a molecule is nonrandom.Rous sarcoma virus (RSV), for example, has an average of 10 to 15 m6A residues per virion RNA molecule (4, 14, 36).These methylated bases have been detected only in the 3' half of the genomic RNA (4), even though sequence analysis shows that putative methylation sites (GAC and AAC) are widely dispersed throughout the molecule (32). Likewise, internal methylation of bovine prolactin mRNA is confined to the 3' two-thirds of the message, with a high concentration of m6A in the 3' noncoding region (17). Simian virus 40 * Corresponding author.(SV40) late mRNAs, on the other hand, each contain an average of three m6As, all near the 5' ends of those messages in translated sequences (7). Adenovirus mRNAs are methylated in the 5' two-thirds of the molecules, and m6As seem, in this system, to be conserved during mRNA processing (9, 33).We have developed a method for directly identifying m6A residues within the genomic RNA of RSV. We have precisely mapped seven such sites in the genome, all within protein coding regions. In addition, we have analyzed the extent of modification at individual methylation sites. Earlier studies with SV40 (7) and with RSV (12) suggest that methylation at some specific sites is heterogeneous, with bas...

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Comparison of methylated sequences in messenger RNA and heterogeneous nuclear RNA from mouse L cells

Cited by 225 publications

References 23 publications

Nonmuscle and muscle tropomyosin isoforms are expressed from a single gene by alternative RNA splicing and polyadenylation.

Nonmuscle and muscle tropomyosin isoforms are expressed from a single gene by alternative RNA splicing and polyadenylation.

Oligopyrimidine tract at the 5' end of mammalian ribosomal protein mRNAs is required for their translational control.

Precise localization of m6A in Rous sarcoma virus RNA reveals clustering of methylation sites: implications for RNA processing.

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