Nuclease activity associated with mammalian mRNA in its native state: possible basis for selectivity in mRNA decay

1990 ◽  
Vol 10 (5) ◽  
pp. 2060-2069
Author(s):  
R Bandyopadhyay ◽  
M Coutts ◽  
A Krowczynska ◽  
G Brawerman
Keyword(s):  
Mammalian Cells ◽  
Nuclease Activity ◽  
Noncoding Region ◽  
Beta Globin ◽  
Native State ◽  
Globin Mrna ◽  
Ribosomal Subunits ◽  
Messenger Ribonucleoprotein ◽  
Mouse Sarcoma ◽  
Actin Mrna

Polysome and messenger ribonucleoprotein (mRNP) preparations from various mammalian cells contain tightly bound nuclease activity that causes degradation of the mRNA in the preparations. This activity was found to cosediment with all polysome size classes as well as with free mRNPs and to remain associated with the mRNPs released from polysomes by treatment with EDTA. No association with ribosomal subunits was evident. The rates of mRNA degradation were not affected by serial dilution, an indication that enzyme and substrate are tightly associated. beta-Globin mRNA in purified reticulocyte polysomes was cleaved at AU sequences in the 3'-terminal region. Cleavages at the same sites occurred when deproteinized reticulocyte RNA was incubated with mouse sarcoma 180 (S-180) polysomes. The S-180 preparations caused additional cleavages, primarily at UG sequences. A P40 mRNA in S-180 polysomes was cleaved primarily in the 3' noncoding region, but the cleavages in a P21 mRNA were seen in the 5' noncoding region only. Actin mRNA was cleaved in an internal region, yielding large relatively stable 3'- and 5'-terminal fragments. These data suggest the occurrence of highly specific interactions between one or more mRNA-bound nucleases and individual mRNA species.

scholarly journals Nuclease activity associated with mammalian mRNA in its native state: possible basis for selectivity in mRNA decay.

1990 ◽  
Vol 10 (5) ◽  
pp. 2060-2069 ◽  
Author(s):  
R Bandyopadhyay ◽  
M Coutts ◽  
A Krowczynska ◽  
G Brawerman
Keyword(s):  
Mammalian Cells ◽  
Nuclease Activity ◽  
Noncoding Region ◽  
Beta Globin ◽  
Native State ◽  
Globin Mrna ◽  
Ribosomal Subunits ◽  
Messenger Ribonucleoprotein ◽  
Mouse Sarcoma ◽  
Actin Mrna

Polysome and messenger ribonucleoprotein (mRNP) preparations from various mammalian cells contain tightly bound nuclease activity that causes degradation of the mRNA in the preparations. This activity was found to cosediment with all polysome size classes as well as with free mRNPs and to remain associated with the mRNPs released from polysomes by treatment with EDTA. No association with ribosomal subunits was evident. The rates of mRNA degradation were not affected by serial dilution, an indication that enzyme and substrate are tightly associated. beta-Globin mRNA in purified reticulocyte polysomes was cleaved at AU sequences in the 3'-terminal region. Cleavages at the same sites occurred when deproteinized reticulocyte RNA was incubated with mouse sarcoma 180 (S-180) polysomes. The S-180 preparations caused additional cleavages, primarily at UG sequences. A P40 mRNA in S-180 polysomes was cleaved primarily in the 3' noncoding region, but the cleavages in a P21 mRNA were seen in the 5' noncoding region only. Actin mRNA was cleaved in an internal region, yielding large relatively stable 3'- and 5'-terminal fragments. These data suggest the occurrence of highly specific interactions between one or more mRNA-bound nucleases and individual mRNA species.

scholarly journals Assembly of 48S Translation Initiation Complexesfrom Purified Components with mRNAs That Have Some Base Pairingwithin Their 5′ UntranslatedRegions

2003 ◽  
Vol 23 (24) ◽  
pp. 8925-8933 ◽  
Author(s):  
Sergei E. Dmitriev ◽  
Ilya M. Terenin ◽  
Yan E. Dunaevsky ◽  
William C. Merrick ◽  
Ivan N. Shatsky
Keyword(s):  
Translation Initiation ◽  
Mammalian Cells ◽  
Ribosomal Subunit ◽  
Initiation Factor ◽  
Beta Globin ◽  
Globin Mrna ◽  
Initiation Factors ◽  
40S Ribosomal Subunit ◽  
Cellular Mrnas ◽  
Actin Mrna

ABSTRACT The reconstitution of translation initiation complexes from purified components is a reliable approach to determine the complete set of essential canonical initiation factors and auxiliary proteins required for the 40S ribosomal subunit to locate the initiation codon on individual mRNAs. Until now, it has been successful mostly for formation of 48S translation initiation complexes with viral IRES elements. Among cap-dependent mRNAs, only globin mRNAs and transcripts with artificial 5′ leaders were amenable to this assembly. Here, with modified conditions for the reconstitution, 48S complexes have been successfully assembled with the 5′ UTR of beta-actin mRNA (84 nucleotides) and the tripartite leader of adenovirus RNAs (232 nucleotides), though the latter has been able to use only the scanning rather then the shunting model of translation initiation with canonical initiation factors. We show that initiation factor 4B is essential for mRNAs that have even a rather moderate base pairing within their 5′ UTRs (with the cumulative stability of the secondary structure within the entire 5′ UTR < −13 kcal/mol) and not essential for beta-globin mRNA. A recombinant eIF4B poorly substitutes for the native factor. The 5′ UTRs with base-paired G residues reveal a very sharp dependence on the eIF4B concentration to form the 48S complex. The data suggest that even small variations in concentration or activity of eIF4B in mammalian cells may differentially affect the translation of different classes of cap-dependent cellular mRNAs.

scholarly journals Positive and Negative Effects of the Major Mammalian Messenger Ribonucleoprotein p50 on Binding of 40 S Ribosomal Subunits to the Initiation Codon of β-Globin mRNA

2002 ◽  
Vol 277 (18) ◽  
pp. 15445-15451 ◽  
Author(s):  
Andrey V. Pisarev ◽  
Maksim A. Skabkin ◽  
Adri A. Thomas ◽  
William C. Merrick ◽  
Lev P. Ovchinnikov ◽  
...  
Keyword(s):  
Initiation Codon ◽  
Negative Effects ◽  
Globin Mrna ◽  
Ribosomal Subunits ◽  
Messenger Ribonucleoprotein

scholarly journals All factors required for protein synthesis are retained on heparin bound to Sepharose

1978 ◽  
Vol 172 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J Hradec ◽  
Z Dušek
Keyword(s):  
Protein Synthesis ◽  
Affinity Chromatography ◽  
Rat Liver ◽  
Mammalian Cells ◽  
Gel Filtration ◽  
Ribosomal Subunits ◽  
Messenger Ribonucleoprotein ◽  
Reticulocyte Lysates ◽  
Sepharose 4B

1. Postmitochondrial supernatants of rabbit reticulocyte lysates were chromatographed on heparin bound to Sepharose 4B, and the fraction retained on affinity columns was separated by subsequent gel filtration on Sepharose 4B into three fractions, two of them active in protein synthesis. 2. The heavier fraction sedimented at 40S and contained more than 10% RNA. This consisted predominantly of a 12S component, with smaller amounts of the 9S and 4S RNA species. The lighter fraction (18-20S) was composed of proteins with less than 1% RNA. 3. Different enzymic activities were associated with these fractions. 4. In the presence of both fractions, efficient translation took place on combined ribosomal subunits of rat liver with added cofactors. Globin messenger ribonucleoprotein stimulated this translation 5-6-fold. 5. Relatively large complexes of all factors required for protein synthesis are apparently isolated from reticulocytes by affinity chromatography on heparin-Sepharose 4B. Such complexes may occur naturally in the cytoplasm of mammalian cells.

scholarly journals The nonamer UUAUUUAUU is the key AU-rich sequence motif that mediates mRNA degradation.

1995 ◽  
Vol 15 (4) ◽  
pp. 2219-2230 ◽  
Author(s):  
A M Zubiaga ◽  
J G Belasco ◽  
M E Greenberg
Keyword(s):  
Mammalian Cells ◽  
Decay Process ◽  
Early Gene ◽  
Sequence Motif ◽  
Gene Products ◽  
Beta Globin ◽  
Globin Mrna ◽  
Early Step ◽  
Rapid Decay ◽  
Multiple Copies

Labile mRNAs that encode cytokine and immediate-early gene products often contain AU-rich sequences within their 3' untranslated region (UTR). These AU-rich sequences appear to be key determinants of the short half-lives of these mRNAs, although the sequence features of these elements and the mechanism by which they target mRNAs for rapid decay have not been fully defined. We have examined the features of AU-rich elements (AREs) that are crucial for their function as determinants of mRNA instability in mammalian cells by testing the ability of various mutant c-fos AREs and synthetic AREs to direct rapid mRNA deadenylation and decay when inserted within the 3' UTR of the normally stable beta-globin mRNA. Evidence is presented that the pentamer AUUUA, which previously was suggested to be the minimal determinant of instability present in mammalian AREs, cannot direct rapid mRNA deadenylation and decay. Instead, the nonomer UUAUUUAUU is the elemental AU-rich sequence motif that destabilizes mRNA. Removal of one uridine residue from either end of the nonamer (UUAUUUAU or UAUUUAUU) results in a decrease of potency of the element, while removal of a uridine residue from both ends of the nonamer (UAUUUAU) eliminates detectable destabilizing activity. The inclusion of an additional uridine residue at both ends of the nonamer (UUUAUUUAUUU) does not further increase the efficacy of the element. Taken together, these findings suggest that the nonamer UUAUUUAUU is the minimal AU-rich motif that effectively destabilizes mRNA. Additional ARE potency is achieved by combining multiple copies of this nonamer in a single mRNA 3' UTR. Furthermore, analysis of poly(A) shortening rates for ARE-containing mRNAs reveals that the UUAUUUAUU sequence also accelerates mRNA deadenylation and suggests that the UUAUUUAUU motif targets mRNA for rapid deadenylation as an early step in the mRNA decay process.

scholarly journals Blood transcriptome analysis of patients with uncomplicated bacterial infection and sepsis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Velma Herwanto ◽  
Benjamin Tang ◽  
Ya Wang ◽  
Maryam Shojaei ◽  
Marek Nalos ◽  
...  
Keyword(s):  
Bacterial Infection ◽  
Healthy Controls ◽  
Beta Globin ◽  
Transcriptome Data ◽  
Valuable Resource ◽  
Globin Mrna ◽  
Blood Samples ◽  
Data Description ◽  
Pathway Activation ◽  
Blood Transcriptome

Abstract Objectives Hospitalized patients who presented within the last 24 h with a bacterial infection were recruited. Participants were assigned into sepsis and uncomplicated infection groups. In addition, healthy volunteers were recruited as controls. RNA was prepared from whole blood, depleted from beta-globin mRNA and sequenced. This dataset represents a highly valuable resource to better understand the biology of sepsis and to identify biomarkers for severe sepsis in humans. Data description The data presented here consists of raw and processed transcriptome data obtained by next generation RNA sequencing from 105 peripheral blood samples from patients with uncomplicated infections, patients who developed sepsis, septic shock patients, and healthy controls. It is provided as raw sequenced reads and as normalized log2 transformed relative expression levels. This data will allow performing detailed analyses of gene expression changes between uncomplicated infections and sepsis patients, such as identification of differentially expressed genes, co-regulated modules as well as pathway activation studies.

Polyomavirus enhancer contains multiple redundant sequence elements that activate both DNA replication and gene expression

1985 ◽  
Vol 5 (4) ◽  
pp. 649-658
Author(s):  
G M Veldman ◽  
S Lupton ◽  
R Kamen
Keyword(s):  
Dna Replication ◽  
Globin Gene ◽  
Mrna Levels ◽  
Beta Globin ◽  
Transcriptional Enhancer ◽  
Globin Mrna ◽  
Enhancer Region ◽  
Sequence Elements ◽  
Multiple Copies ◽  
A Site

Sequences that comprise the 244-base-pair polyomavirus enhancer region are also required in cis for viral DNA replication (Tyndall et al., Nucleic Acids Res. 9:6231-6250, 1981). We have studied the relationship between the sequences that activate replication and those that enhance transcription in two ways. One approach, recently described by de Villiers et al. (Nature [London], 312:242-246, 1984), in which the polyomavirus enhancer region was replaced with other viral or cellular transcriptional enhancers suggested that an enhancer function is required for polyomavirus DNA replication. The other approach, described in this paper, was to analyze a series of deletion mutants that functionally dissect the enhancer region and enabled us to localize four sequence elements in this region that are involved in the activation of replication. These elements, which have little sequence homology, are functionally redundant. Element A (nucleotides 5108 through 5130) was synthesized as a 26-mer with XhoI sticky ends, and one or more copies were introduced into a plasmid containing the origin of replication, but lacking the enhancer region. Whereas one copy of the 26-mer activated replication only to 2 to 5% of the wild-type level, two copies inserted in either orientation completely restored replication. We found that multiple copies of the 26-mer were also active as a transcriptional enhancer by measuring the beta-globin mRNA levels expressed from a plasmid that contained either the polyomavirus enhancer or one or more copies of the 26-mer inserted in a site 3' to the beta-globin gene. We observed a correlation between the number of inserted 26-mers and the level of beta-globin RNA expression.

scholarly journals Stability of alpha and beta globin messenger RNA during induced differentiation of mouse erythroleukemia cells

Blood ◽  
1979 ◽  
Vol 54 (4) ◽  
pp. 933-939
Author(s):  
R Gambari ◽  
RA Rifkind ◽  
PA Marks
Keyword(s):  
Messenger Rna ◽  
Erythroid Differentiation ◽  
Beta Globin ◽  
Globin Mrna ◽  
Induced Differentiation ◽  
Hexamethylene Bisacetamide ◽  
Erythroleukemia Cells ◽  
Mrna Content ◽  
Murine Erythroleukemia ◽  
Murine Erythroleukemia Cells

Murine erythroleukemia cells (MELC) are induced to express erythroid differentiation when cultured with hexamethylene bisacetamide (HMBA). Newly synthesized alpha and beta globin mRNA are both relatively stable, half-life (t1/2) greater than 50 hr, early in the course of induced differentiation. In fully induced cells there is a decrease in stability of both newly synthesized alpha and beta globin mRNA. The decay of alpha mRNA is faster, (t 1/2, 10--12 hr) than beta globin mRNA (t1/2, 20--22 hr). Thus, differences in stability of alpha and beta globin mRNA plays a role in determining the ratio of alpha to beta mRNA content in differentiated erythroid cells.

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