scholarly journals MicroRNAs control translation initiation by inhibiting eukaryotic initiation factor 4E/cap and poly(A) tail function

2005 ◽  
Vol 102 (47) ◽  
pp. 16961-16966 ◽  
Author(s):  
D. T. Humphreys ◽  
B. J. Westman ◽  
D. I. K. Martin ◽  
T. Preiss
Keyword(s):  
Translation Initiation ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Eukaryotic Initiation Factor 4E ◽  
Control Translation ◽  
Tail Function

scholarly journals Cap-binding protein (eukaryotic initiation factor 4E) and 4E-inactivating protein BP-1 independently regulate cap-dependent translation.

1996 ◽  
Vol 16 (10) ◽  
pp. 5450-5457 ◽  
Author(s):  
D Feigenblum ◽  
R J Schneider
Keyword(s):  
Heat Shock ◽  
Translation Initiation ◽  
Binding Protein ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Metaphase Arrest ◽  
Animal Cells ◽  
Eukaryotic Initiation Factor 4E ◽  
Dependent Protein

Cap-dependent protein synthesis in animal cells is inhibited by heat shock, serum deprivation, metaphase arrest, and infection with certain viruses such as adenovirus (Ad). At a mechanistic level, translation of capped mRNAs is inhibited by dephosphorylation of eukaryotic initiation factor 4E (eIF-4E) (cap-binding protein) and its physical sequestration with the translation repressor protein BP-1 (PHAS-I). Dephosphorylation of BP-I blocks cap-dependent translation by promoting sequestration of eIF-4E. Here we show that heat shock inhibits translation of capped mRNAs by simultaneously inducing dephosphorylation of eIF-4E and BP-1, suggesting that cells might coordinately regulate translation of capped mRNAs by impairing both the activity and the availability of eIF-4E. Like heat shock, late Ad infection is shown to induce dephosphorylation of eIF-4E. However, in contrast to heat shock, Ad also induces phosphorylation of BP-1 and release of eIF-4E. BP-1 and eIF-4E can therefore act on cap-dependent translation in either a mutually antagonistic or cooperative manner. Three sets of experiments further underscore this point: (i) rapamycin is shown to block phosphorylation of BP-1 without inhibiting dephosphorylation of eIF-4E induced by heat shock or Ad infection, (ii) eIF-4E is efficiently dephosphorylated during heat shock or Ad infection regardless of whether it is in a complex with BP-1, and (iii) BP-1 is associated with eIF-4E in vivo regardless of the state of eIF-4E phosphorylation. These and other studies establish that inhibition of cap-dependent translation does not obligatorily involve sequestration of eIF-4E by BP-1. Rather, translation is independently regulated by the phosphorylation states of eIF-4E and the 4E-binding protein, BP-1. In addition, these results demonstrate that BP-1 and eIF-4E can act either in concert or in opposition to independently regulate cap-dependent translation. We suggest that independent regulation of eIF-4E and BP-1 might finely regulate the efficiency of translation initiation or possibly control cap-dependent translation for fundamentally different purposes.

scholarly journals The distribution of eukaryotic initiation factor 4E after bouts of resistance exercise is altered by shortening of recovery periods

2020 ◽  
Vol 70 (1) ◽  
Author(s):  
Junya Takegaki ◽  
Riki Ogasawara ◽  
Karina Kouzaki ◽  
Satoshi Fujita ◽  
Koichi Nakazato ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Resistance Exercise ◽  
Translation Initiation ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Related Factors ◽  
Eukaryotic Initiation Factor 4E

Abstract Insufficient duration of recovery between resistance exercise bouts reduces the effects of exercise training, but the influence on muscle anabolic responses is not fully understood. Here, we investigated the changes in the distribution of eukaryotic initiation factor (eIF) 4E, a key regulator of translation initiation, and related factors in mouse skeletal muscle after three successive bouts of resistance exercise with three durations of recovery periods (72 h: conventional, 24 h: shorter, and 8 h: excessively shorter). Bouts of resistance exercise dissociated eIF4E from eIF4E binding protein 1, with the magnitude increasing with shorter recovery. Whereas bouts of resistance exercise with 72 h recovery increased the association of eIF4E and eIF4G, those with shorter recovery did not. Similar results were observed in muscle protein synthesis. These results suggest that insufficient recovery inhibited the association of eIF4E and eIF4G, which might cause attenuation of protein synthesis activation after bouts of resistance exercise.

scholarly journals Dynamic Interaction of Eukaryotic Initiation Factor 4G1 (eIF4G1) with eIF4E and eIF1 Underlies Scanning-Dependent and -Independent Translation

2018 ◽  
Vol 38 (18) ◽  
Author(s):  
Ora Haimov ◽  
Urmila Sehrawat ◽  
Ana Tamarkin-Ben Harush ◽  
Anat Bahat ◽  
Anna Uzonyi ◽  
...  
Keyword(s):  
Binding Site ◽  
Translation Initiation ◽  
Dynamic Interaction ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Leaky Scanning ◽  
Eukaryotic Initiation Factor 4E ◽  
Independent Translation

ABSTRACTTranslation initiation of most mRNAs involves m7G-cap binding, ribosomal scanning, and AUG selection. Initiation from an m7G-cap-proximal AUG can be bypassed resulting in leaky scanning, except for mRNAs bearing thetranslationinitiator ofshort 5′untranslated region (TISU) element. m7G-cap binding is mediated by the eukaryotic initiation factor 4E (eIF4E)-eIF4G1 complex. eIF4G1 also associates with eIF1, and both promote scanning and AUG selection. Understanding of the dynamics and significance of these interactions is lacking. We report that eIF4G1 exists in two complexes, either with eIF4E or with eIF1. Using an eIF1 mutant impaired in eIF4G1 binding, we demonstrate that eIF1-eIF4G1 interaction is important for leaky scanning and for avoiding m7G-cap-proximal initiation. Intriguingly, eIF4E-eIF4G1 antagonizes the scanning promoted by eIF1-eIF4G1 and is required for TISU. In mapping the eIF1-binding site on eIF4G1, we unexpectedly found that eIF4E also binds it indirectly. These findings uncover the RNA features underlying regulation by eIF4E-eIF4G1 and eIF1-eIF4G1 and suggest that 43S ribosome transition from the m7G-cap to scanning involves relocation of eIF4G1 from eIF4E to eIF1.

scholarly journals Phosphorylation of eukaryotic initiation factor 4E (eIF4E) at Ser209 is not required for protein synthesis in vitro and in vivo

2001 ◽  
Vol 268 (20) ◽  
pp. 5375-5385 ◽  
Author(s):  
Linda McKendrick ◽  
Simon J. Morley ◽  
Virginia M. Pain ◽  
Rosemary Jagus ◽  
Bhavesh Joshi
Keyword(s):  
Protein Synthesis ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Eukaryotic Initiation Factor 4E

Thermodynamics of Molecular Recognition of mRNA 5′ Cap by Yeast Eukaryotic Initiation Factor 4E

2011 ◽  
Vol 115 (27) ◽  
pp. 8746-8754 ◽  
Author(s):  
Katarzyna Kiraga-Motoszko ◽  
Anna Niedzwiecka ◽  
Anna Modrak-Wojcik ◽  
Janusz Stepinski ◽  
Edward Darzynkiewicz ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Eukaryotic Initiation Factor 4E
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