Nuclear Ribonucleoprotein Particles Containing Messenger Ribonucleic Acid

Samarina, O. P.; Krichevskaya, A. A.; Georgiev, G.P.

doi:10.1038/2101319a0

Cited by 107 publications

(33 citation statements)

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“…Properties of the Particles in Cytoplasm As already observed by others [9,18] sedimentation rates for RNA and for nucleoprotein particles depend strongly on the suspension medium. The same was observed when released nuclear particles (tentatively designated as 30 S particles in accordance with Samarina et al [12,17]) were mixed 1:l with cytoplasm; they then cosedimented with the small (45s) subribosomal particles (Fig.7). The same was observed when purified nuclear particles labelled with A 300ml culture was labelled for 30min with 200pC r3H]uridine and half of the culture was fractionated as described in Materials and Methods.…”

Section: Sixes Of Rnas Obtained From Nuclear Particlesmentioning

confidence: 50%

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Particles of Nuclear Origin Carrying Rapidly Labelled RNA

Köhler

Arends

1968

Eur J Biochem

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Nuclei of KB cells have been isolated and incubated at 37" in pH 8.0 saline. The experia) Isolated nuclei release well defined nucleoprotein particles, which contain RNAs not deb) These particles carry rapidly labelled RNA. c) In cytoplasm they cosediment with the long known smaller ribosomal particles. d) Chase experiments suggest that nuclear particles are precursors of cytoplasmic particles. ments described in this paper provide evidence that: tectable in untreated nuclei.In higher organisms the bulk of cellular RNA, e. g. 25 S and 18 S ribosomal RNAs, messenger-and transfer RNAs, are synthesized within the nucleus on the chromosomes [l]. The center of activity of these RNAs, namely the polysomes, are on the other hand exclusively located in the cytoplasm. Ribosomal and messenger RNAs of the same sizes as those obtained from polysomes are not found in the nucleus. I n contrast, nuclei bf mammalian cells contain types of RNA having a relatively high sedimentation rate (> 30 S), which is supposed to reflect a high molecular weight and a great chain length. Such molecules, however, are not found in the cytoplasm [ 2 ] . Previous research has accumulated evidence that RNA has to pass the nuclear membrane in order to get to the cytoplasm. It is then apparently on this passage that such RNA is cut to the required sizes [3,4].In the cytoplasm newly synthesized rapidly labelled RNAs, do not appear as free molecules, but are bound to small particles, e . g. either pre-ribosomal particles or informosomes [3,5-81. The synthesis and/or the passage of the M e r e n t RNA species differs strongly. The smaller 45 S subunits of the ribosomes are labelled faster with radioactive precursors than the larger 60 S subunits; it is obvious that the two enter the cytoplasm independently, and that the 45 S particle is transferred a t a higher rate.This could imply that it is synthesized a t higher rates also.From our own work [6] and from experiments of Girard and collaborators [9], it is further evident that messenger-RNA is the very first to leave the nucleus.Unusual Abbreviations. niRNA, messenger RNA; tRNA. transfer RNA.Note. The sedimentation coefficients of the particles and RNA species discussed here are approximate and were not dotermincd. The values are adopted from the publications cited. They are used to name the hitherto nameless particles and RNA species.

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Section: Sixes Of Rnas Obtained From Nuclear Particlesmentioning

confidence: 50%

“…It will be shown in the following that incubation of isolated mammalian nuclei in a saline solution a t pH 8 which was first described by Samarina, Krichevskaya, and Georgiev [12], is well suited to obtain a ribonucleoprotein fraction conveniently. No other solutions, either hypotonic or isotonic or hypertonic, gave comparable results [13].…”

mentioning

confidence: 99%

Particles of Nuclear Origin Carrying Rapidly Labelled RNA

Köhler

Arends

1968

Eur J Biochem

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“…To date, two sets have been identified : hnRNP and snRNP proteins. The hnRNP proteins, which number at least 24, have been defined by biochemical cofractionation with radiolabeled hnRNA (Samarina et al, 1966;Beyer et al ., 1977) and more recently by immunochemical analysis (Pifiol-Roma et al, 1988) . Several genes encoding hnRNP proteins have been cloned and at least one protein has been shown to interact directly with RNA in vitro (Merrill et al, 1988) .…”

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A conserved family of nuclear phosphoproteins localized to sites of polymerase II transcription.

Roth

Zahler

Stolk

1991

The Journal of Cell Biology

320

279

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Abstract. An antibody was identified previously that recognizes sites of polymerase II transcription on lampbrush chromosomes, puffs on polytene chromosomes, and many small granules in the nucleoplasm of all cells tested . This antibody binds a conserved family of phosphorylated polypeptides in vertebrate and invertebrate cells . We developed a method for purifying these proteins that involves differential solubility in MgC12. We N ASCENT transcripts are bound by proteins, concomitant with synthesis by polymerase II . This was demonstrated in observations of ribonuclease treated amphibian lampbrush chromosomes (Gall and Callan, 1962) where it is possible to see nascent protein-bound transcripts by light microscopy, and was later confirmed by a number of studies in other systems (Malcolm and Sommerville, 1974;Lamb and Daneholt, 1979). Electron microscopic studies of transcription units using spreading techniques developed by Miller and colleagues confirmed this observation (Miller and Bakken, 1972).Because of their role in the elaboration ofgenetic information, there has been a major effort to identify transcriptbinding proteins. To date, two sets have been identified : hnRNP and snRNP proteins. The hnRNP proteins, which number at least 24, have been defined by biochemical cofractionation with radiolabeled hnRNA (Samarina et al., 1966;Beyer et al ., 1977) and more recently by immunochemical analysis (Pifiol-Roma et al., 1988) . Several genes encoding hnRNP proteins have been cloned and at least one protein has been shown to interact directly with RNA in vitro (Merrill et al., 1988) . Twelve snRNP proteins were identified by co-immunoprecipitation with snRNAs using an antibody that recognized a common epitope found on these proteins (Lerner and Steitz, 1979).We show here that a mAb 104 (mAb104), described as binding to lateral loops on amphibian lampbrush chromosomes (Roth et al., 1990) and to puffs on Drosophila polytene chromosomes (unpublished observation) binds a previously undescribed conserved family of nuclear phosphoproteins . Antigens recognized by mAbl04 do not coprecipitate with anti-hnRNP antibodies (Roth et al., 1990). We have cloned a gene that encodes a mAb104 immunoreactive protein from Drosophila melanogaster The encoded protein shares sequence homology with proteins involved in pre-mRNA splic-© The Rockefeller University Press, 0021-9525/91/11/587/10 $2 .00 The Journal of Cell Biology, Volume 115, Number 3, November 1991587-596 isolated a Drosophila cDNA encoding one of the proteins using information obtained from microsequencing . In vivo expression studies show that this protein is concentrated on sites of polymerase II transcription and that it is highly phosphorylated . The protein shares a high degree of homology with proteins involved in alternative splicing of pre-mRNA suggesting the possibility that this protein plays a role in pre-mRNA splicing .ing. We show that heterogeneously-sized RNA-but not snRNÁs-coprecipitate using mAb104 . Based on these experiments as well as in vivo expressio...

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“…Nuclear 30-S ribonucleoproteins were prepared according to Samarina et al [3], with the exception that Tris was substituted by triethanolamine : the nuclei pellet was washed with 10 mM triethanolamine . HCl, pH 7.0, containing 140 mM NaCl and 1 mM MgCI2, and was extracted three times with 1 -2 vol.…”

Section: Isolation Of Rat Liver Nuclear 30-s Ribonucleoproteinsmentioning

confidence: 99%

“…The term informosomes was suggested to denote these particles [l, 21. Three classes of such particles are distinguished: nuclear ribonucleoproteins [3,4], free cytoplasmic informosomes [l, 2,5] and polyribosomal messenger ribonucleoproteins 16 -81. Together with informosomes a special fraction of RNA-binding proteins is also present in the cytoplasm [9] and nucleus [lo]; these proteins are capable of interacting with RNA and forming artificial ribonucleoprotein particles similar to informosomes in their sedimentation coefficients and buoyant density values.…”

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confidence: 99%

A Comparison of the RNA-Binding Proteins with the Proteins of Polyribosomal Messenger Ribonucleoproteins in Rabbit Reticulocytes

Ovchinnikov¹,

Seriakova²,

Alzhanova³

et al. 1978

Eur J Biochem

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The complete set of rabbit reticulocyte PNA-binding proteins was compared with the proteins of rabbit reticulocyte polyribosomal messenger ribonucleoproteins as well as with the proteins of rat liver nuclear 30-S ribonucleoprotein particles, using electrophoresis in polyacrylamide gel in the presence of sodium dodecylsulfate. The purity of the two ribonucleoprotein preparations was 90 % and 95 %, respectively. Rabbit reticulocyte RNA-binding proteins included main polypeptide chains of three sizes with molecular weights of about 95000, 49000 and 36000. Rabbit reticulocyte polyribosomal messenger ribonucleoproteins with a sedimentation coefficient of about 13 S and a buoyant density of 1.48 g/cm3 in CsCl were shown to contain polypeptide chains of four sizes with molecular weights of about 78000,49000,46000 and 33000. Rat liver nuclear 30-S ribonucleoprotein particles with a buoyant density of 1.41 -1.43 g/cm3 in CsCl contained polypeptide chains of two sizes with molecular weights of about 40000 and 37000. A parallel electrophoresis of the RNAbinding proteins and proteins of the ribonucleoprotein particles as well as the electrophoresis of their mixtures showed that one of the main RNA-binding proteins with a molecular weight of 49000 is indistinguishable from the corresponding protein of polyribosomal messenger ribonucleoproteins. The two other RNA-binding proteins could not be detected in the polyribosomal messenger ribonucleoproteins. The polypeptides contained in nuclear 30-S ribonucleoprotein particles were found neither in polyribosomal messenger ribonucleoproteins nor among RNA-binding proteins.In eukaryotic cells all messenger RNA is complexed with protein and thus present in the form of ribonucleoprotein particles characterized by a comparatively low buoyant density in CsCl (about 1.4 g/cm3). The term informosomes was suggested to denote these particles [l, 21. Three classes of such particles are distinguished: nuclear ribonucleoproteins [3,4], free cytoplasmic informosomes [l, 2,5] and polyribosomal messenger ribonucleoproteins 16 -81. Together with informosomes a special fraction of RNA-binding proteins is also present in the cytoplasm [9] and nucleus [lo]; these proteins are capable of interacting with RNA and forming artificial ribonucleoprotein particles similar to informosomes in their sedimentation coefficients and buoyant density values.Many studies in the last few years have been performed to determine protein compositions of the particles of the different classes and to compare them with each other. However, most of them can be regarded as only preliminary due to the absence of appropriate guarantees of purity of the preparations analyzed from protein contamination. Here we propose a method of evaluating protein contamination in ribonucleoprotein particle preparations and compare the complete set of cytoplasmic RNA-binding proteins of rabbit reticulocytes with the proteins of polyribosoinal messenger ribonucleoproteins (90% protein purity) of the same cells, on the one hand, and rat liver nuc...

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Nuclear Ribonucleoprotein Particles Containing Messenger Ribonucleic Acid

Cited by 107 publications

References 3 publications

Particles of Nuclear Origin Carrying Rapidly Labelled RNA

Particles of Nuclear Origin Carrying Rapidly Labelled RNA

A conserved family of nuclear phosphoproteins localized to sites of polymerase II transcription.

A Comparison of the RNA-Binding Proteins with the Proteins of Polyribosomal Messenger Ribonucleoproteins in Rabbit Reticulocytes

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