Differential stimulation of capped mRNA translation in vitro by cap binding protein

Nature ◽  
1980 ◽  
Vol 285 (5763) ◽  
pp. 331-333 ◽  
Author(s):  
N. Sonenberg ◽  
H. Trachsel ◽  
S. Hecht ◽  
A. J. Shatkin
Keyword(s):  
Binding Protein ◽  
Mrna Translation ◽  
Stimulation Of

scholarly journals Epigenetic Modifications During Sex Change Repress Gonadotropin Stimulation of Cyp19a1a in a Teleost Ricefield Eel (Monopterus albus)

Endocrinology ◽  
2013 ◽  
Vol 154 (8) ◽  
pp. 2881-2890 ◽  
Author(s):  
Yang Zhang ◽  
Shen Zhang ◽  
Zhixin Liu ◽  
Lihong Zhang ◽  
Weimin Zhang
Keyword(s):  
Dna Methylation ◽  
Binding Protein ◽  
Sex Change ◽  
Gonadal Development ◽  
Proximal Region ◽  
Histone Deacetylation ◽  
Epigenetic Mechanisms ◽  
Gonadal Differentiation ◽  
Stimulation Of

Abstract In vertebrates, cytochrome P450 aromatase, encoded by cyp19a1, converts androgens to estrogens and plays important roles in gonadal differentiation and development. The present study examines whether epigenetic mechanisms are involved in cyp19a1a expression and subsequent gonadal development in the hermaphroditic ricefield eel. The expression of the ricefield eel cyp19a1a was stimulated by gonadotropin via the cAMP pathway in the ovary but not the ovotestis or testis. The CpG within the cAMP response element (CRE) of the cyp19a1a promoter was hypermethylated in the ovotestis and testis compared with the ovary. The methylation levels of CpG sites around CRE in the distal region (region II) and around steroidogenic factor 1/adrenal 4 binding protein sites and TATA box in the proximal region (region I) were inversely correlated with cyp19a1a expression during the natural sex change from female to male. In vitro DNA methylation decreased the basal and forskolin-induced activities of cyp19a1a promoter. Chromatin immunoprecipitation assays indicated that histone 3 (Lys9) in both regions I and II of the cyp19a1a promoter were deacetylated and trimethylated in the testis, and in contrast to the ovary, phosphorylated CRE-binding protein failed to bind to these regions. Lastly, the DNA methylation inhibitor 5-aza-2′-deoxycytidine reversed the natural sex change of ricefield eels. These results suggested that epigenetic mechanisms involving DNA methylation and histone deacetylation and methylation may abrogate the stimulation of cyp19a1a by gonadotropins in a male-specific fashion. This may be a mechanism widely used to drive natural sex change in teleosts as well as gonadal differentiation in other vertebrates.

scholarly journals Binding of eukaryotic translation initiation factor 4E (eIF4E) to eIF4G represses translation of uncapped mRNA.

1997 ◽  
Vol 17 (12) ◽  
pp. 6876-6886 ◽  
Author(s):  
S Z Tarun ◽  
A B Sachs
Keyword(s):  
Translation Initiation ◽  
Mrna Translation ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Eukaryotic Translation Initiation Factor ◽  
Eukaryotic Translation ◽  
Eukaryotic Translation Initiation ◽  
Stimulation Of

mRNA translation in crude extracts from the yeast Saccharomyces cerevisiae is stimulated by the cap structure and the poly(A) tail through the binding of the cap-binding protein eukaryotic translation initiation factor 4E (eIF4E) and the poly(A) tail-binding protein Pab1p. These proteins also bind to the translation initiation factor eIF4G and thereby link the mRNA to the general translational apparatus. In contrast, uncapped, poly(A)-deficient mRNA is translated poorly in yeast extracts, in part because of the absence of eIF4E and Pab1p binding sites on the mRNA. Here, we report that uncapped-mRNA translation is also repressed in yeast extracts due to the binding of eIF4E to eIF4G. Specifically, we find that mutations which weaken the eIF4E binding site on the yeast eIF4G proteins Tif4631p and Tif4632p lead to temperature-sensitive growth in vivo and the stimulation of uncapped-mRNA translation in vitro. A mutation in eIF4E which disturbs its ability to interact with eIF4G also leads to a stimulation of uncapped-mRNA translation in vitro. Finally, overexpression of eIF4E in vivo or the addition of excess eIF4E in vitro reverses these effects of the mutations. These data support the hypothesis that the eIF4G protein can efficiently stimulate translation of exogenous uncapped mRNA in extracts but is prevented from doing so as a result of its association with eIF4E. They also suggest that some mRNAs may be translationally regulated in vivo in response to the amount of free eIF4G in the cell.

scholarly journals Regulation of Poly(ADP-Ribose) Polymerase 1 Activity by Y-Box-Binding Protein 1

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1325
Author(s):  
Konstantin N. Naumenko ◽  
Mariya V. Sukhanova ◽  
Loic Hamon ◽  
Tatyana A. Kurgina ◽  
Elizaveta E. Alemasova ◽  
...  
Keyword(s):  
Ternary Complex ◽  
Binding Protein ◽  
Terminal Part ◽  
Force Microscopy ◽  
Atomic Force ◽  
Synthesis Activity ◽  
Positively Charged ◽  
Stimulation Of ◽  
Damaged Dna

Y-box-binding protein 1 (YB-1) is a multifunctional positively charged protein that interacts with DNA or RNA and poly(ADP-ribose) (PAR). YB-1 is poly(ADP-ribosyl)ated and stimulates poly(ADP-ribose) polymerase 1 (PARP1) activity. Here, we studied the mechanism of YB-1-dependent PAR synthesis by PARP1 in vitro using biochemical and atomic force microscopy assays. PAR synthesis activity of PARP1 is known to be facilitated by co-factors such as Mg2+. However, in contrast to an Mg2+-dependent reaction, the activation of PARP1 by YB-1 is accompanied by overall up-regulation of protein PARylation and shortening of the PAR polymer. Therefore, YB-1 and cation co-factors stimulated PAR synthesis in divergent ways. PARP1 autoPARylation in the presence of YB-1 as well as trans-PARylation of YB-1 are greatly affected by the type of damaged DNA, suggesting that PARP1 activation depends on the formation of a PARP1–YB-1–DNA ternary complex. An unstructured C-terminal part of YB-1 involved in an interaction with PAR behaves similarly to full-length YB-1, indicating that both DNA and PAR binding are involved in the stimulation of PARP1 activity by YB-1. Thus, YB-1 is likely linked to the regulation of PARylation events in cells via an interaction with PAR and damaged DNA.

Translation of poly(A)-binding protein mRNA is regulated by growth conditions

1992 ◽  
Vol 70 (9) ◽  
pp. 770-778 ◽  
Author(s):  
Lloyd C. Berger ◽  
Jnanankur Bag ◽  
Bruce H. Sells
Keyword(s):  
Binding Protein ◽  
Elevated Serum ◽  
Mrna Translation ◽  
Serum Levels ◽  
Bimodal Distribution ◽  
Growth Conditions ◽  
Translational Efficiency ◽  
Resting Cells ◽  
Translation Control

Translational efficiency of a minor group of mRNAs is regulated by serum levels in 3T6 fibroblasts. Included within this group is the poly(A)-binding protein (PABP) mRNA. We analyzed the distribution of PABP mRNA in polysome profiles and found a large percentage of this mRNA to be translationally repressed in both actively growing (~ 60%) and resting cells (~ 70%). Elevated serum levels induced a distinct bimodal distribution of this mRNA between actively translated and repressed fractions. Similarly, treatment of cells with low doses of cycloheximide also generated a partial shift of repressed PABP mRNA into the actively translated fraction. In an attempt to characterize the factors which regulate PABP mRNA translation we have identified the proteins which bind to this mRNA in vitro. Sequences within the 5′ untranslated region were found to be sufficient for binding of all proteins to this mRNA. We suggest that this region and the proteins associated with it may be essential for translation control of PABP mRNA.Key words: translation, mRNP, poly(A) binding protein.

Stimulation of Ki-ras Ribozyme Activity by RNA Binding Protein, NCp7, in Vitro and in Pancreatic Tumor Cell Line, Capan 1

1994 ◽  
Vol 733 (1 Molecular and) ◽  
pp. 113-121 ◽  
Author(s):  
KARIN MOELLING ◽  
GERD MUELLER ◽  
JENS DANNULL ◽  
CHRISTOPH REUSS ◽  
PETER BEIMLING ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cell Line ◽  
Pancreatic Tumor ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Tumor Cell Line ◽  
Pancreatic Tumor Cell ◽  
Stimulation Of

scholarly journals Chaperone Hsp27 inhibits translation during heat shock by binding eIF4G and facilitating dissociation of cap-initiation complexes

2000 ◽  
Vol 14 (12) ◽  
pp. 1460-1470
Author(s):  
Rafael Cuesta ◽  
Gaurav Laroia ◽  
Robert J. Schneider
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Binding Protein ◽  
Adaptor Protein ◽  
Mrna Translation ◽  
Cellular Protein ◽  
In Vitro Translation ◽  
Unfolded Proteins ◽  
Murine Homolog

Inhibition of protein synthesis during heat shock limits accumulation of unfolded proteins that might damage eukaryotic cells. We demonstrate that chaperone Hsp27 is a heat shock-induced inhibitor of cellular protein synthesis. Translation of most mRNAs requires formation of a cap-binding initiation complex known as eIF4F, consisting of factors eIF4E, eIF4A, eIF4E kinase Mnk1, poly(A)-binding protein, and adaptor protein eIF4G. Hsp27 specifically bound eIF4G during heat shock, preventing assembly of the cap-initiation/eIF4F complex and trapping eIF4G in insoluble heat shock granules. eIF4G is a specific target of Hsp27, as eIF4E, eIF4A, Mnk1, poly(A)-binding protein, eIF4B, and eIF3 were not bound by Hsp27 and were not recruited into insoluble complexes. Dissociation of eIF4F was enhanced during heat shock by ectopic overexpression of Hsp25, the murine homolog of human Hsp27. Overexpression of Hsc70, a constitutive homolog of Hsp70, prevented loss of cap-initiation complexes and maintained eIF4G solubility. Purified Hsp27 specifically bound purified eIF4G in vitro, prevented in vitro translation, eliminated eIF4G interaction with protein binding factors, and promoted eIF4G insolubilization. These results therefore demonstrate that Hsp27 is a heat-induced inhibitor of eIF4F-dependent mRNA translation.

scholarly journals CPEB3-mediated MTDH mRNA translational suppression restrains hepatocellular carcinoma progression

2020 ◽  
Vol 11 (9) ◽  
Author(s):  
He Zhang ◽  
Chendan Zou ◽  
Zini Qiu ◽  
Fang E ◽  
Qiang Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cancer Progression ◽  
Rna Binding ◽  
Epithelial Mesenchymal Transition ◽  
Binding Protein ◽  
Mrna Translation ◽  
Luciferase Assay ◽  
Mesenchymal Transition

Abstract Cytoplasmic polyadenylation element-binding protein 3 (CPEB3) is a sequence-specific RNA-binding protein. We had reported that CPEB3 is involved in hepatocellular carcinoma (HCC) progression. However, the underlying mechanisms of CPEB3 in HCC remain unclear. In this study, we firstly performed RNA immunoprecipitation to uncover the transcriptome-wide CPEB3-bound mRNAs (CPEB3 binder) in HCC. Bioinformatic analysis indicates that CPEB3 binders are closely related to cancer progression, especially HCC metastasis. Further studies confirmed that metadherin (MTDH) is a direct target of CPEB3. CPEB3 can suppress the translation of MTDH mRNA in vivo and in vitro. Besides, luciferase assay demonstrated that CPEB3 interacted with 3′-untranslated region of MTDH mRNA and inhibited its translation. Subsequently, CPEB3 inhibited the epithelial–mesenchymal transition and metastasis of HCC cells through post-transcriptional regulation of MTDH. In addition, cpeb3 knockout mice are more susceptible to carcinogen-induced hepatocarcinogenesis and subsequent lung metastasis. Our results also indicated that CPEB3 was a good prognosis marker, which is downregulated in HCC tissue. In conclusion, our results demonstrated that CPEB3 played an important role in HCC progression and targeting CPEB3-mediated mRNA translation might be a favorable therapeutic approach.

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