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

The rate of synthesis in Chinese hamster cells of 5' cap structures, m7 GpppNmp, in large (greater than 700 bases) heterogeneous nuclear ribonucleic acid (RNA) molecules is two to three times faster than the synthesis of 3'-terminal polyadenylic acid segments. As judged by presence of caps, newly synthesized polysomal messenger RNA, exclusive of messenger RNA the size of histone messenger RNA, is more than 90% in the polyadenylated category. It appears, therefore, that between half and two-thirds of the long capped heterogeneous nuclear RNA molecules do not contribute a capped polysomal derivative to the cytoplasm. There are capped, nonpolysomal, non-polyadenylated molecules with a rapid turnover rate that fractionate with the cytoplasm. These metabolically unstable molecules either could represent leakage into the cytoplasm during fractionation or could truly spend a brief time in the cytoplasm before decay.

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Nuclear RNA-protein interactions and messenger RNA processing.

The Journal of Cell Biology ◽

10.1083/jcb.97.5.1321 ◽

1983 ◽

Vol 97 (5) ◽

pp. 1321-1326 ◽

Cited By ~ 32

Author(s):

T Pederson

Keyword(s):

Detailed Analysis ◽

Recent Work ◽

Protein Interactions ◽

Rna Processing ◽

Messenger Rna ◽

Mammalian Cells ◽

General Hypothesis ◽

Ribonucleoprotein Particles ◽

Nuclear Rna ◽

Nuclear Ribonucleoprotein

Eucaryotic messenger RNA precursors are processed in nuclear ribonucleoprotein particles (hnRNP). Here recent work on the structure of hnRNP is reviewed, with emphasis on function. Detailed analysis of a specific case, the altered assembly of hnRNP in heat-shocked Drosophila and mammalian cells, leads to a general hypothesis linking hnRNP structure and messenger RNA processing.

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II. Distribution of DNA base sequences - Introductory remarks: DNA and genes

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1978.0029 ◽

1978 ◽

Vol 283 (997) ◽

pp. 305-307

Keyword(s):

Genetic Code ◽

Messenger Rna ◽

Transfer Rnas ◽

Rna Molecules ◽

Dna Base ◽

Base Sequences ◽

Nuclear Rna

After the genetic code was discovered in the early 1960s, it was generally accepted that nearly all DNA in higher organisms was used to specify messenger RNA molecules at some time during their development. A small fraction could be set aside for the ribosomal and transfer RNAs and there was a problem about the rapidly turning over nuclear RNA which did not appear in the cytoplasm as message. By and large we considered that most DNA was potentially coding and the lone voices who talked of other kinds of DNA on the basis of somewhat flimsy evidence were largely ignored.

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A COMPARISON BETWEEN HETEROGENEOUS NUCLEAR RNA AND POLYSOMAL MESSENGER RNA IN HELA CELLS BY RNA-DNA HYBRIDIZATION

The Journal of Cell Biology ◽

10.1083/jcb.44.3.467 ◽

1970 ◽

Vol 44 (3) ◽

pp. 467-475 ◽

Cited By ~ 54

Author(s):

Ruy Soeiro ◽

James E. Darnell

Keyword(s):

Hela Cell ◽

Hela Cells ◽

Dna Hybridization ◽

Messenger Rna ◽

Sequence Similarity ◽

Nuclear Rna ◽

Hybridization Reaction

Heterogeneous nuclear RNA (HnRNA) and mRNA from cytoplasmic polyribosomes of HeLa cells have been compared by RNA-DNA hybridization tests. 1 µg of HeLa cell DNA binds 0.05–0.10 µg of either HnRNA or mRNA. In addition, HeLa DNA that is preexposed to unlabeled HnRNA was found to have a reduced capacity to bind either HnRNA or mRNA. The results are compatible with considerable sequence similarity in the two types of RNA but, as is discussed, firm conclusions are precluded by imperfections of the hybridization reaction as presently employed.

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