Glucocorticoids selectively inhibit translation of ribosomal protein mRNAs in P1798 lymphosarcoma cells

1987 ◽  
Vol 7 (8) ◽  
pp. 2691-2699 ◽  
Author(s):  
O Meyuhas ◽  
E A Thompson ◽  
R P Perry
Keyword(s):  
Ribosomal Protein ◽  
Translational Control ◽  
Ribosomal Proteins ◽  
Mrna Translation ◽  
Substantial Decrease ◽  
Rrna Synthesis ◽  
Dexamethasone Treatment ◽  
Selective Suppression

When P1798 murine lymphosarcoma cells are exposed to 10(-7) M dexamethasone, there is a dramatic inhibition of rRNA synthesis, which is completely reversible when the hormone is withdrawn. In the present experiments we examined whether dexamethasone treatment causes any alteration in the accumulation or utilization of mRNAs that encode ribosomal proteins (rp mRNAs). No effect on the accumulation of six different rp mRNAs was detected. However, the translation of five of six rp mRNAs was selectively inhibited in the presence of the hormone, as judged by a substantial decrease in ribosomal loading. Normal translation of rp mRNA was resumed within a few hours after hormone withdrawal. In untreated or fully recovered cells, the distribution of rp mRNAs between polyribosomes and free ribonucleoprotein is distinctly bimodal, suggesting that rp mRNAs are subject to a particular form of translational control in which they are either translationally inactive or fully loaded with ribosomes. A possible relationship between this mode of translational control and the selective suppression of rp mRNA translation by glucocorticoids is discussed.

scholarly journals Glucocorticoids selectively inhibit translation of ribosomal protein mRNAs in P1798 lymphosarcoma cells.

1987 ◽  
Vol 7 (8) ◽  
pp. 2691-2699 ◽  
Author(s):  
O Meyuhas ◽  
E A Thompson ◽  
R P Perry
Keyword(s):  
Ribosomal Protein ◽  
Translational Control ◽  
Ribosomal Proteins ◽  
Mrna Translation ◽  
Substantial Decrease ◽  
Rrna Synthesis ◽  
Dexamethasone Treatment ◽  
Selective Suppression

When P1798 murine lymphosarcoma cells are exposed to 10(-7) M dexamethasone, there is a dramatic inhibition of rRNA synthesis, which is completely reversible when the hormone is withdrawn. In the present experiments we examined whether dexamethasone treatment causes any alteration in the accumulation or utilization of mRNAs that encode ribosomal proteins (rp mRNAs). No effect on the accumulation of six different rp mRNAs was detected. However, the translation of five of six rp mRNAs was selectively inhibited in the presence of the hormone, as judged by a substantial decrease in ribosomal loading. Normal translation of rp mRNA was resumed within a few hours after hormone withdrawal. In untreated or fully recovered cells, the distribution of rp mRNAs between polyribosomes and free ribonucleoprotein is distinctly bimodal, suggesting that rp mRNAs are subject to a particular form of translational control in which they are either translationally inactive or fully loaded with ribosomes. A possible relationship between this mode of translational control and the selective suppression of rp mRNA translation by glucocorticoids is discussed.

scholarly journals Ribosomal protein S7 ubiquitination during ER stress in yeast is associated with selective mRNA translation and stress outcome

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yasuko Matsuki ◽  
Yoshitaka Matsuo ◽  
Yu Nakano ◽  
Shintaro Iwasaki ◽  
Hideyuki Yoko ◽  
...  
Keyword(s):  
Er Stress ◽  
Ribosomal Protein ◽  
Translational Control ◽  
Ribosomal Proteins ◽  
Translational Regulation ◽  
Mrna Translation ◽  
Ribosome Profiling ◽  
Independent Manner ◽  
Eif2α Phosphorylation ◽  
The Unfolded Protein Response

AbstracteIF2α phosphorylation-mediated translational regulation is crucial for global translation repression by various stresses, including the unfolded protein response (UPR). However, translational control during UPR has not been demonstrated in yeast. This study investigated ribosome ubiquitination-mediated translational controls during UPR. Tunicamycin-induced ER stress enhanced the levels of ubiquitination of the ribosomal proteins uS10, uS3 and eS7. Not4-mediated monoubiquitination of eS7A was required for resistance to tunicamycin, whereas E3 ligase Hel2-mediated ubiquitination of uS10 was not. Ribosome profiling showed that the monoubiquitination of eS7A was crucial for translational regulation, including the upregulation of the spliced form of HAC1 (HAC1i) mRNA and the downregulation of Histidine triad NucleoTide-binding 1 (HNT1) mRNA. Downregulation of the deubiquitinating enzyme complex Upb3-Bre5 increased the levels of ubiquitinated eS7A during UPR in an Ire1-independent manner. These findings suggest that the monoubiquitination of ribosomal protein eS7A plays a crucial role in translational controls during the ER stress response in yeast.

scholarly journals Ribosomal protein S7 ubiquitination during ER stress in yeast is associated with selective mRNA translation and stress outcome

2020 ◽  
Author(s):  
Yasuko Matsuki ◽  
Yoshitaka Matsuo ◽  
Yu Nakano ◽  
Shintaro Iwasaki ◽  
Hideyuki Yoko ◽  
...  
Keyword(s):  
Er Stress ◽  
Ribosomal Protein ◽  
Translational Control ◽  
Ribosomal Proteins ◽  
Translational Regulation ◽  
Mrna Translation ◽  
Ribosome Profiling ◽  
Independent Manner ◽  
Eif2α Phosphorylation ◽  
The Unfolded Protein Response

ABSTRACTeIF2α phosphorylation-mediated translational regulation is crucial for global translation repression by various stresses, including the unfolded protein response (UPR). However, translational control during UPR has not been demonstrated in yeast. This study investigated ribosome ubiquitination-mediated translational controls during UPR. Tunicamycin-induced ER stress enhanced the levels of ubiquitination of the ribosomal proteins uS10, uS3 and eS7. Not4-mediated monoubiquitination of eS7A was required for resistance to tunicamycin, whereas E3 ligase Hel2-mediated ubiquitination of uS10 was not. Ribosome profiling showed that the monoubiquitination of eS7A was crucial for translational regulation, including the upregulation of the spliced form of HAC1 (HAC1i) mRNA and the downregulation of Histidine triad NucleoTide-binding 1 (HNT1) mRNA. Downregulation of the deubiquitinating enzyme complex Upb3-Bre5 increased the levels of ubiquitinated eS7A during UPR in an Ire1-independent manner. These findings suggest that the monoubiquitination of ribosomal protein eS7A plays a crucial role in translational controls during the ER stress response in yeast.

Developmental expression and 5S rRNA-binding activity of Xenopus laevis ribosomal protein L5

1989 ◽  
Vol 9 (12) ◽  
pp. 5281-5288
Author(s):  
W M Wormington
Keyword(s):  
Ribosomal Protein ◽  
Mammalian Cells ◽  
Ribosomal Proteins ◽  
5S Rrna ◽  
Yeast Cells ◽  
Developmental Expression ◽  
Rrna Synthesis ◽  
Ribosome Assembly ◽  
Subunit Assembly ◽  
Ribosomal Protein L5

Ribosomal protein L5 binds specifically to 5S rRNA to form a complex that is a precursor to 60S subunit assembly in vivo. Analyses in yeast cells, mammalian cells, and Xenopus embryos have shown that the accumulation of L5 is not coordinated with the expression of other ribosomal proteins. In this study, the primary structure and developmental expression of Xenopus ribosomal protein L5 were examined to determine the basis for its distinct regulation. These analyses showed that L5 expression could either coincide with 5S rRNA synthesis and ribosome assembly or be controlled independently of these events at different stages of Xenopus development. L5 synthesis during oogenesis was uncoupled from the accumulation of 5S rRNa but coincided with subunit assembly. In early embryos, the inefficient translation of L5 mRNA resulted in the accumulation of a stable L5-5S rRNA complex before ribosome assembly at later stages of development. Additional results demonstrated that L5 protein synthesized in vitro bound specifically to 5S rRNA.

scholarly journals Developmental expression and 5S rRNA-binding activity of Xenopus laevis ribosomal protein L5.

1989 ◽  
Vol 9 (12) ◽  
pp. 5281-5288 ◽  
Author(s):  
W M Wormington
Keyword(s):  
Ribosomal Protein ◽  
Mammalian Cells ◽  
Ribosomal Proteins ◽  
5S Rrna ◽  
Yeast Cells ◽  
Developmental Expression ◽  
Rrna Synthesis ◽  
Ribosome Assembly ◽  
Subunit Assembly ◽  
Ribosomal Protein L5

Ribosomal protein L5 binds specifically to 5S rRNA to form a complex that is a precursor to 60S subunit assembly in vivo. Analyses in yeast cells, mammalian cells, and Xenopus embryos have shown that the accumulation of L5 is not coordinated with the expression of other ribosomal proteins. In this study, the primary structure and developmental expression of Xenopus ribosomal protein L5 were examined to determine the basis for its distinct regulation. These analyses showed that L5 expression could either coincide with 5S rRNA synthesis and ribosome assembly or be controlled independently of these events at different stages of Xenopus development. L5 synthesis during oogenesis was uncoupled from the accumulation of 5S rRNa but coincided with subunit assembly. In early embryos, the inefficient translation of L5 mRNA resulted in the accumulation of a stable L5-5S rRNA complex before ribosome assembly at later stages of development. Additional results demonstrated that L5 protein synthesized in vitro bound specifically to 5S rRNA.

scholarly journals A memory of eS25 loss drives resistance phenotypes

2020 ◽  
Author(s):  
Alex G Johnson ◽  
Ryan A Flynn ◽  
Christopher P Lapointe ◽  
Yaw Shin Ooi ◽  
Michael L Zhao ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Translational Control ◽  
Ribosomal Proteins ◽  
Ribosomal Protein Gene ◽  
Human Cell Line ◽  
Cellular Protein ◽  
Ribosomal Protein Genes ◽  
Genomic Locus ◽  
Cellular Phenotypes

Abstract In order to maintain cellular protein homeostasis, ribosomes are safeguarded against dysregulation by myriad processes. Remarkably, many cell types can withstand genetic lesions of certain ribosomal protein genes, some of which are linked to diverse cellular phenotypes and human disease. Yet the direct and indirect consequences from these lesions are poorly understood. To address this knowledge gap, we studied in vitro and cellular consequences that follow genetic knockout of the ribosomal proteins RPS25 or RACK1 in a human cell line, as both proteins are implicated in direct translational control. Prompted by the unexpected detection of an off-target ribosome alteration in the RPS25 knockout, we closely interrogated cellular phenotypes. We found that multiple RPS25 knockout clones display viral- and toxin-resistance phenotypes that cannot be rescued by functional cDNA expression, suggesting that RPS25 loss elicits a cell state transition. We characterized this state and found that it underlies pleiotropic phenotypes and has a common rewiring of gene expression. Rescuing RPS25 expression by genomic locus repair failed to correct for the phenotypic and expression hysteresis. Our findings illustrate how the elasticity of cells to a ribosome perturbation can drive specific phenotypic outcomes that are indirectly linked to translation and suggests caution in the interpretation of ribosomal protein gene mutation data.

Saccharomyces cerevisiae coordinates accumulation of yeast ribosomal proteins by modulating mRNA splicing, translational initiation, and protein turnover

1985 ◽  
Vol 5 (6) ◽  
pp. 1512-1521
Author(s):  
J R Warner ◽  
G Mitra ◽  
W F Schwindinger ◽  
M Studeny ◽  
H M Fried
Keyword(s):  
Yeast Cell ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Mrna Translation ◽  
Mrna Splicing ◽  
Ribosomal Protein Genes ◽  
Translational Initiation ◽  
Initiation Of Translation ◽  
Precursor Rna ◽  
Autogenous Regulation

The rate of accumulation of each ribosomal protein is carefully regulated by the yeast cell to provide the equimolar ratio necessary for the assembly of the ribosome. The mechanisms responsible for this regulation have been examined by introducing into the yeast cell extra copies of seven individual ribosomal protein genes carried on autonomously replicating plasmids. In each case studied the plasmid-borne gene was transcribed to the same degree as the genomic gene. Nevertheless, the cell maintained a balanced accumulation of ribosomal proteins, using a variety of methods other than transcription. (i) Several ribosomal proteins were synthesized in substantial excess. However, the excess ribosomal protein was rapidly degraded. (ii) The excess mRNA for two of the ribosomal protein genes was translated inefficiently. We provide evidence that this was due to inefficient initiation of translation. (iii) The transcripts derived from two of the ribosomal protein genes were spliced inefficiently, leading to an accumulation of precursor RNA. We present a model which proposes the autogenous regulation of mRNA splicing as a eucaryotic parallel of the autogenous regulation of mRNA translation in procaryotes. Finally, the accumulation of each ribosomal protein was regulated independently. In no instance did the presence of excess copies of the gene for one ribosomal protein affect the synthesis of another ribosomal protein.

scholarly journals Roles of Transcriptional and Translational Control Mechanisms in Regulation of Ribosomal Protein Synthesis in Escherichia coli

2017 ◽  
Vol 199 (21) ◽  
Author(s):  
Hector L. Burgos ◽  
Kevin O'Connor ◽  
Patricia Sanchez-Vazquez ◽  
Richard L. Gourse
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Ribosomal Protein ◽  
Translational Control ◽  
High Energy ◽  
Rrna Synthesis ◽  
Nucleoside Triphosphate ◽  
Control Mechanisms ◽  
Content Type ◽  
Nutritional Conditions

ABSTRACT Bacterial ribosome biogenesis is tightly regulated to match nutritional conditions and to prevent formation of defective ribosomal particles. In Escherichia coli, most ribosomal protein (r-protein) synthesis is coordinated with rRNA synthesis by a translational feedback mechanism: when r-proteins exceed rRNAs, specific r-proteins bind to their own mRNAs and inhibit expression of the operon. It was recently discovered that the second messenger nucleotide guanosine tetra and pentaphosphate (ppGpp), which directly regulates rRNA promoters, is also capable of regulating many r-protein promoters. To examine the relative contributions of the translational and transcriptional control mechanisms to the regulation of r-protein synthesis, we devised a reporter system that enabled us to genetically separate the cis-acting sequences responsible for the two mechanisms and to quantify their relative contributions to regulation under the same conditions. We show that the synthesis of r-proteins from the S20 and S10 operons is regulated by ppGpp following shifts in nutritional conditions, but most of the effect of ppGpp required the 5′ region of the r-protein mRNA containing the target site for translational feedback regulation and not the promoter. These results suggest that most regulation of the S20 and S10 operons by ppGpp following nutritional shifts is indirect and occurs in response to changes in rRNA synthesis. In contrast, we found that the promoters for the S20 operon were regulated during outgrowth, likely in response to increasing nucleoside triphosphate (NTP) levels. Thus, r-protein synthesis is dynamic, with different mechanisms acting at different times. IMPORTANCE Bacterial cells have evolved complex and seemingly redundant strategies to regulate many high-energy-consuming processes. In E. coli, synthesis of ribosomal components is tightly regulated with respect to nutritional conditions by mechanisms that act at both the transcription and translation steps. In this work, we conclude that NTP and ppGpp concentrations can regulate synthesis of ribosomal proteins, but most of the effect of ppGpp is indirect as a consequence of translational feedback in response to changes in rRNA levels. Our results illustrate how effects of seemingly redundant regulatory mechanisms can be separated in time and that even when multiple mechanisms act concurrently their contributions are not necessarily equivalent.

Deficiency of dietary EAA preferentially inhibits mRNA translation of ribosomal proteins in liver of meal-fed rats

2001 ◽  
Vol 281 (3) ◽  
pp. E430-E439 ◽  
Author(s):  
Tracy G. Anthony ◽  
Ali K. Reiter ◽  
Joshua C. Anthony ◽  
Scot R. Kimball ◽  
Leonard S. Jefferson
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Serum Insulin ◽  
Control Diet ◽  
Mrna Translation ◽  
Initiation Factor ◽  
Liver Protein ◽  
Deficient Diet

The goal of these studies was to investigate the mechanisms by which amino acid supply regulates global rates of protein synthesis as well as the translation of ribosomal protein (rp) mRNAs in liver. In the experiments conducted, male weanling rats were trained over a 2-wk period to consume their daily food intake within 3 h. On day 14, rats were fed the control diet or an isocaloric, isonitrogenous diet lacking glycine, tryptophan, leucine, or the branched-chain amino acids (BCAA) for 1 h. Feeding Trp-, Leu-, or BCAA-deficient diets resulted in significant reductions in serum insulin, hepatic protein synthesis, eukaryotic initiation factor 2B (eIF2B) activity, and phosphorylation of eIF4E-binding protein 1 (4E-BP1) and ribosomal protein S6 kinase (S6K1). Phosphorylation of eIF2α was inversely related to eIF2B activity under all conditions. Alterations in the hepatic synthesis of rp were assessed by changes in the distribution of rp (S4, S8, L26) mRNAs across sucrose density gradients and compared with non-rp (β-actin, albumin) mRNAs. In all dietary treatments, non-rp mRNAs were mostly polysome associated. Conversely, the proportion of rp mRNAs residing in polysomes was two- to fivefold less in rats fed diets lacking tryptophan, leucine, or BCAA compared with rats fed the control diet. Total hepatic abundance of all mRNAs examined did not differ among treatment groups. For all parameters examined, there were no differences between rats fed the glycine-deficient diet and rats fed the control diet. The data suggest that essential amino acid (EAA) deficiency inhibits global rates of liver protein synthesis via a block in translation initiation. Additionally, the translation of rp mRNAs is preferentially repressed in association with decreased S6K1 phosphorylation.

scholarly journals Saccharomyces cerevisiae coordinates accumulation of yeast ribosomal proteins by modulating mRNA splicing, translational initiation, and protein turnover.

1985 ◽  
Vol 5 (6) ◽  
pp. 1512-1521 ◽  
Author(s):  
J R Warner ◽  
G Mitra ◽  
W F Schwindinger ◽  
M Studeny ◽  
H M Fried
Keyword(s):  
Yeast Cell ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Mrna Translation ◽  
Mrna Splicing ◽  
Ribosomal Protein Genes ◽  
Translational Initiation ◽  
Initiation Of Translation ◽  
Precursor Rna ◽  
Autogenous Regulation

The rate of accumulation of each ribosomal protein is carefully regulated by the yeast cell to provide the equimolar ratio necessary for the assembly of the ribosome. The mechanisms responsible for this regulation have been examined by introducing into the yeast cell extra copies of seven individual ribosomal protein genes carried on autonomously replicating plasmids. In each case studied the plasmid-borne gene was transcribed to the same degree as the genomic gene. Nevertheless, the cell maintained a balanced accumulation of ribosomal proteins, using a variety of methods other than transcription. (i) Several ribosomal proteins were synthesized in substantial excess. However, the excess ribosomal protein was rapidly degraded. (ii) The excess mRNA for two of the ribosomal protein genes was translated inefficiently. We provide evidence that this was due to inefficient initiation of translation. (iii) The transcripts derived from two of the ribosomal protein genes were spliced inefficiently, leading to an accumulation of precursor RNA. We present a model which proposes the autogenous regulation of mRNA splicing as a eucaryotic parallel of the autogenous regulation of mRNA translation in procaryotes. Finally, the accumulation of each ribosomal protein was regulated independently. In no instance did the presence of excess copies of the gene for one ribosomal protein affect the synthesis of another ribosomal protein.

Sign in / Sign up

Export Citation Format

Share Document