Identification and characterization of the packaging proteins of core 40S hnRNP particles

Beyer, Ann L.; Christensen, Mark E.; Walker, Barbara; LeStourgeon, Wallace M.

doi:10.1016/0092-8674(77)90323-3

Cited by 465 publications

(393 citation statements)

References 43 publications

Supporting

Mentioning

365

Contrasting

Unclassified

Order By: Relevance

“…2 A) . The Friend cell hnRNP proteins are complex but, as in all the other eukaryotic cells previously investigated (5,15,18,33,34), there is a major component of 38,000 mol wt ("p38") . The hnRNP contains very little protein of <38,000 mol wt, indicating the absence of nucleolar ribosomal precursor particles (37), which contain proteins of mainly 15,000-55,000 daltons (25).…”

Section: Isolation Of Hnrnp Particles From Friend Cell Nucleimentioning

confidence: 99%

“…Initial attempts to extract these hnRNP particles from nuclei resulted in the isolation of degraded, 40S RNP complexes (43), because of the action of endogenous nucleases. While these early degraded RNP preparations were of value for some purposes, such as enumerating the minimal set of proteins present in these so-called "core" particles (5,18,30), the fact remains that the 40S RNPs contain highly degraded hnRNA fragments and therefore cannot be regarded as native structures .…”

Section: Identification Of Covalently Intact (3-globin Mrna Precursomentioning

confidence: 99%

See 1 more Smart Citation

Messenger RNA processing and nuclear structure: isolation of nuclear ribonucleoprotein particles containing beta-globin messenger RNA precursors.

Pederson¹,

Davis²

1980

The Journal of Cell Biology

View full text Add to dashboard Cite

To explore the relationships between transcription, messenger RNA (mRNA) processing, and nuclear structure, ribonucleoprotein particles containing heterogeneous nuclear RNA (hnRNP) have been purified from globin-producing mouse Friend erythroleukemia cells. These nuclear hnRNP particles sediment at 50S-2005 and contain, in addition to high molecular weight hnRNA, a specific set of nuclear proteins predominated by a major component of 38,000 mol wt . The hnRNP particles are free of histones and ribosomal structural proteins, indicating their purification from the two other major nucleoprotein components of the nucleus: chromatin and nucleolar ribosomal precursor RNP particles. The authenticity of the Friend cell hnRNP particles is demonstrated by the results of reconstruction experiments with deproteinized hnRNA, and by the resistance of the particles to dissociation during isopycnic banding in C5 2SO 4 gradients without prior aldehyde fixation . Hybridization analysis with cloned mouse 8-globin DNA demonstrates that hnRNP particles from induced Friend cells contain newly synthesized transcripts of the a-globin gene . Agarose gel electrophoresis of hnRNP particle-derived RNA denatured in glyoxal followed by "Northern" transfer to diazobenzyloxymethyl paper and hybridization with 32 P-labeled cloned mouse fl-globin DNA reveals the presence in hnRNP of two size classes of /3-globin gene transcripts, the larger of which corresponds to the pre-spliced 15S 8-globin mRNA precursor previously identified in whole nuclear RNA, and the smaller of which corresponds to completely processed 9S a-globin mRNA . These results establish, for the first time, that the nuclear transcripts of a specific, welldefined eukaryotic structural gene can be isolated in an RNP particle form, and that their RNP structure persists throughout mRNA splicing .The transcription of structural genes in the eukaryotic cell nucleus takes place at a nucleoprotein level of organization . This is true of both the templates for transcription, chromatin (reviewed in reference 36), and the products of transcription, heterogeneous nuclear RNA, which is rapidly assembled into ribonucleoprotein particles known as hnRNP (33,34). However, the functional significance of these nucleoprotein environments for transcription and hnRNA metabolism is not understood . As a step toward defining the relationships between messenger RNA (mRNA) processing and nuclear structure, hnRNP particles have been purified from globin-producing mouse Friend erythroleukemia cells and characterized with particular reference to transcripts of the 8-globin gene. The THE JOURNAL OF CELL BIOLOGY -VOLUME 87 OCTOBER 1980 47-54 © The Rockefeller University Press -0021-9525/80/10/0047/08 $1 .00 major conclusion is that both pre-spliced and spliced mRNA sequences have a ribonucleoprotein structure in the nucleus. MATERIALS AND METHODSCell Culture, Radioisotopic Labeling, and Cell Fractionation Clone 745 mouse Friend erythroleukemia cells were maintained in monolayer culture usingJoklik-mod...

show abstract

Section: Isolation Of Hnrnp Particles From Friend Cell Nucleimentioning

confidence: 99%

Section: Identification Of Covalently Intact (3-globin Mrna Precursomentioning

confidence: 99%

Messenger RNA processing and nuclear structure: isolation of nuclear ribonucleoprotein particles containing beta-globin messenger RNA precursors.

Pederson¹,

Davis²

1980

The Journal of Cell Biology

View full text Add to dashboard Cite

show abstract

“…As for the chemical nature of the trans-acting factor, a diffusible factor, such as a protein or nucleoprotein, is the most obvious candidate, although the relevance of differences in pH and/or salt concentration (Schmitt et al, 1987) cannot be excluded. In the nucleus, precursor mRNA forms heterogeneous nuclear ribonucleoprotein (hnRNP) by complexing with > 20 different proteins (Beyer et al, 1977;Pinol-Roma et al, 1988). Some hnRNP proteins have been implicated in premRNA splicing (Choi et al, 1986;Mayrand et al, 1986).…”

Section: Trans-acting Factormentioning

confidence: 99%

Regulation of tissue-specific alternative splicing: exon-specific cis-elements govern the splicing of leukocyte common antigen pre-mRNA.

1989

View full text Add to dashboard Cite

show abstract

“…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) .…”

mentioning

confidence: 99%

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

Roth

Zahler

Stolk

1991

The Journal of Cell Biology

320

278

View full text Add to dashboard Cite

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...

show abstract

Identification and characterization of the packaging proteins of core 40S hnRNP particles

Cited by 465 publications

References 43 publications

Messenger RNA processing and nuclear structure: isolation of nuclear ribonucleoprotein particles containing beta-globin messenger RNA precursors.

Messenger RNA processing and nuclear structure: isolation of nuclear ribonucleoprotein particles containing beta-globin messenger RNA precursors.

Regulation of tissue-specific alternative splicing: exon-specific cis-elements govern the splicing of leukocyte common antigen pre-mRNA.

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

Contact Info

Product

Resources

About