Impaired exercise-induced mitochondrial biogenesis in the obese Zucker rat, despite PGC-1α induction, is due to compromised mitochondrial translation elongation

2014 ◽  
Vol 306 (5) ◽  
pp. E503-E511 ◽  
Author(s):  
Nicholas P. Greene ◽  
Mats I. Nilsson ◽  
Tyrone A. Washington ◽  
David E. Lee ◽  
Lemuel A. Brown ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Mitochondrial Protein ◽  
Elongation Factor ◽  
High Volume ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Zucker Rats ◽  
Mitochondrial Translation ◽  
Translation Elongation ◽  
Exercise Induced

Previously, we demonstrated that high-volume resistance exercise stimulates mitochondrial protein synthesis (a measure of mitochondrial biogenesis) in lean but not obese Zucker rats. Here, we examined factors involved in regulating mitochondrial biogenesis in the same animals. PGC-1α was 45% higher following exercise in obese but not lean animals compared with sedentary counterparts. Interestingly, exercised animals demonstrated greater PPARδ protein in both lean (47%) and obese (>200%) animals. AMPK phosphorylation (300%) and CPT-I protein (30%) were elevated by exercise in lean animals only, indicating improved substrate availability/flux. These findings suggest that, despite PGC-1α induction, obese animals were resistant to exercise-induced synthesis of new mitochondrial and oxidative protein. Previously, we reported that most anabolic processes are upregulated in these same obese animals regardless of exercise, so the purpose of this study was to assess specific factors associated with the mitochondrial genome as possible culprits for impaired mitochondrial biogenesis. Exercise resulted in higher mRNA contents of mitochondrial transcription factor A (∼50% in each phenotype) and mitochondrial translation initiation factor 2 (31 and 47% in lean and obese, respectively). However, mitochondrial translation elongation factor-Tu mRNA was higher following exercise in lean animals only (40%), suggesting aberrant regulation of mitochondrial translation elongation as a possible culprit in impaired mitochondrial biogenesis following exercise with obesity.

scholarly journals S. cerevisiae Strain Lacking Mitochondrial IF3 Shows Increased Levels of Tma19p during Adaptation to Respiratory Growth

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 645 ◽  
Author(s):  
Levitskii ◽  
Baleva ◽  
Chicherin ◽  
Krasheninnikov ◽  
Kamenski
Keyword(s):  
Mitochondrial Protein ◽  
Carbon Sources ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Mitochondrial Translation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Gene Coding ◽  
Slow Adaptation ◽  
Respiratory Growth ◽  
Translation Initiation Factor 3

After billions of years of evolution, mitochondrion retains its own genome, which gets expressed in mitochondrial matrix. Mitochondrial translation machinery rather differs from modern bacterial and eukaryotic cytosolic systems. Any disturbance in mitochondrial translation drastically impairs mitochondrial function. In budding yeast Saccharomyces cerevisiae, deletion of the gene coding for mitochondrial translation initiation factor 3 - AIM23, leads to an imbalance in mitochondrial protein synthesis and significantly delays growth after shifting from fermentable to non-fermentable carbon sources. Molecular mechanism underlying this adaptation to respiratory growth was unknown. Here, we demonstrate that slow adaptation from glycolysis to respiration in the absence of Aim23p is accompanied by a gradual increase of cytochrome c oxidase activity and by increased levels of Tma19p protein, which protects mitochondria from oxidative stress.

scholarly journals Isolating and Characterizing Genes Differentially Expressed Early in Apple Fruit Development

1997 ◽  
Vol 122 (6) ◽  
pp. 752-757 ◽  
Author(s):  
Yi-Hu Dong ◽  
Bart-J. Janssen ◽  
Lara R.F. Bieleski ◽  
Ross G. Atkinson ◽  
Bret A.M. Morris ◽  
...  
Keyword(s):  
Elongation Factor ◽  
Gene Families ◽  
Apple Fruit ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Cdna Clones ◽  
Translation Elongation ◽  
Initiation Factor 2 ◽  
Genes Encoding ◽  
Translation Initiation Factor 2

A cDNA library was constructed from apples (Malus ×domestica Borkh.) harvested 1 week after anthesis (WAA). Four cDNA clones differentially hybridized to cDNAs from fruit picked 1 WAA versus cDNAs from fruit harvested 8 WAA and flower buds. The mRNAs corresponding to these cDNA clones—pAFD101 through 104—accumulated in the early stages of apple development, with highest levels at 2 to 4 WAA. The mRNA of pAFD104 was detected only in fruit tissue, while mRNAs for the other three clones were expressed at various levels in a range of tissues. Sequence analysis showed that pAFD101 had high homology to genes encoding the translation elongation factor 1α (EF-1α); pAFD102 had homology to the β-subunit of translation initiation factor 2 (eIF-2β); pAFD104 showed strong similarity to a proline-rich protein and to auxin down-regulated genes; while pAFD103 had no significant homology to any sequences in the databases. Genomic Southern hybridization showed that genes corresponding to all four cDNAs were representatives of small gene families present in the apple genome.

scholarly journals Yeast Mitochondrial Translation Initiation Factor 3 Interacts with Pet111p to Promote COX2 mRNA Translation

2020 ◽  
Vol 21 (10) ◽  
pp. 3414
Author(s):  
Ivan Chicherin ◽  
Sergey Levitskii ◽  
Maria V. Baleva ◽  
Igor A. Krasheninnikov ◽  
Maxim V. Patrushev ◽  
...  
Keyword(s):  
Translation Initiation ◽  
Mitochondrial Protein ◽  
Mrna Translation ◽  
Translation Initiation Factor ◽  
Yeast Cells ◽  
Initiation Factor ◽  
Specific Factor ◽  
Mitochondrial Translation ◽  
Respiratory Chain Complexes ◽  
Translation Initiation Factor 3

Mitochondrial genomes code for several core components of respiratory chain complexes. Thus, mitochondrial translation is of great importance for the organelle as well as for the whole cell. In yeast, mitochondrial translation initiation factor 3, Aim23p, is not essential for the organellar protein synthesis; however, its absence leads to a significant quantitative imbalance of the mitochondrial translation products. This fact points to a possible specific action of Aim23p on the biosynthesis of some mitochondrial protein species. In this work, we examined such peculiar effects of Aim23p in relation to yeast mitochondrial COX2 mRNA translation. We show that Aim23p is indispensable to this process. According to our data, this is mediated by Aimp23p interaction with the known specific factor of the COX2 mRNA translation, Pet111p. If there is no Aim23p in the yeast cells, an increased amount of Pet111p ensures proper COX2 mRNA translation. Our results demonstrate the additional non-canonical function of initiation factor 3 in yeast mitochondrial translation.

scholarly journals Inhibition of eEF2K synergizes with glutaminase inhibitors or 4EBP1 depletion to suppress growth of triple-negative breast cancer cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
YoungJun Ju ◽  
Yaacov Ben-David ◽  
Daniela Rotin ◽  
Eldad Zacksenhaus
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Translation Initiation ◽  
Triple Negative ◽  
Elongation Factor ◽  
Protein Translation ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Related Factors ◽  
Metabolic Conditions

AbstractThe eukaryotic elongation factor-2 kinase, eEF2K, which restricts protein translation elongation, has been identified as a potential therapeutic target for diverse types of malignancies including triple negative breast cancer (TNBC). However, the contexts in which eEF2K inhibition is essential in TNBC and its consequences on the proteome are largely unknown. Here we show that genetic or pharmacological inhibition of eEF2K cooperated with glutamine (Gln) starvation, and synergized with glutaminase (GLS1) inhibitors to suppress growth of diverse TNBC cell lines. eEF2K inhibition also synergized with depletion of eukaryotic translation initiation factor 4E-binding protein 1 (eIF4EBP1; 4EBP1), a suppressor of eukaryotic protein translation initiation factor 4E (eIF4E), to induce c-MYC and Cyclin D1 expression, yet attenuate growth of TNBC cells. Proteomic analysis revealed that whereas eEF2K depletion alone uniquely induced Cyclin Dependent Kinase 1 (CDK1) and 6 (CDK6), combined depletion of eEF2K and 4EBP1 resulted in overlapping effects on the proteome, with the highest impact on the ‘Collagen containing extracellular matrix’ pathway (e.g. COL1A1), as well as the amino-acid transporter, SLC7A5/LAT1, suggesting a regulatory loop via mTORC1. In addition, combined depletion of eEF2K and 4EBP1 indirectly reduced the levels of IFN-dependent innate immune response-related factors. Thus, eEF2K inhibition triggers cell cycle arrest/death under unfavourable metabolic conditions such as Gln-starvation/GLS1 inhibition or 4EBP1 depletion, uncovering new therapeutic avenues for TNBC and underscoring a pressing need for clinically relevant eEF2K inhibitors.

Rpm2, the Protein Subunit of Mitochondrial RNase P in Saccharomyces cerevisiae, Also Has a Role in the Translation of Mitochondrially Encoded Subunits of Cytochrome c Oxidase

Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 573-585
Author(s):  
Vilius Stribinskis ◽  
Guo-Jian Gao ◽  
Steven R Ellis ◽  
Nancy C Martin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Protein ◽  
Nuclear Gene ◽  
Rnase P ◽  
Wild Type ◽  
Protein Subunit ◽  
Mitochondrial Translation

Abstract RPM2 is a Saccharomyces cerevisiae nuclear gene that encodes the protein subunit of mitochondrial RNase P and has an unknown function essential for fermentative growth. Cells lacking mitochondrial RNase P cannot respire and accumulate lesions in their mitochondrial DNA. The effects of a new RPM2 allele, rpm2-100, reveal a novel function of RPM2 in mitochondrial biogenesis. Cells with rpm2-100 as their only source of Rpm2p have correctly processed mitochondrial tRNAs but are still respiratory deficient. Mitochondrial mRNA and rRNA levels are reduced in rpm2-100 cells compared to wild type. The general reduction in mRNA is not reflected in a similar reduction in mitochondrial protein synthesis. Incorporation of labeled precursors into mitochondrially encoded Atp6, Atp8, Atp9, and Cytb protein was enhanced in the mutant relative to wild type, while incorporation into Cox1p, Cox2p, Cox3p, and Var1p was reduced. Pulse-chase analysis of mitochondrial translation revealed decreased rates of translation of COX1, COX2, and COX3 mRNAs. This decrease leads to low steady-state levels of Cox1p, Cox2p, and Cox3p, loss of visible spectra of aa3 cytochromes, and low cytochrome c oxidase activity in mutant mitochondria. Thus, RPM2 has a previously unrecognized role in mitochondrial biogenesis, in addition to its role as a subunit of mitochondrial RNase P. Moreover, there is a synthetic lethal interaction between the disruption of this novel respiratory function and the loss of wild-type mtDNA. This synthetic interaction explains why a complete deletion of RPM2 is lethal.

scholarly journals Validation of Real-time PCR Reference Genes of Muscle Metabolism in Harvested Spiny-Cheek Crayfish (Faxonius limosus) Exposed to Seasonal Variation

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1140
Author(s):  
Natalia Śmietana ◽  
Remigiusz Panicz ◽  
Małgorzata Sobczak ◽  
Piotr Eljasik ◽  
Przemysław Śmietana
Keyword(s):  
Real Time ◽  
Calcium Binding ◽  
Reference Genes ◽  
Target Genes ◽  
Arginine Kinase ◽  
Elongation Factor ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Systematic Analysis ◽  
Key Species

Real-time quantitative reverse transcription PCR (RT-qPCR) is a sensitive and broadly used technique of assessing gene activity. To obtain a reliable result, stably expressed reference genes are essential for normalization of transcripts in various samples. To our knowledge, this is the first systematic analysis of reference genes for normalization of RT-qPCR data in spiny-cheek crayfish (Faxonius limosus). In this study, expression of five candidate reference genes (actb, β-actin; gapdh, glyceraldehyde-3-phosphate dehydrogenase; eif, eukaryotic translation initiation factor 5a; ef-1α, elongation factor-1α; and tub, α-tubulin) in muscle samples from male and female F. limosus in spring and autumn was analyzed. Additionally, the most stable reference genes were used for accurate normalization of five target genes, i.e., tnnc, troponin c; ak, arginine kinase; fr, ferritin; ccbp-23, crustacean calcium-binding protein 23; and actinsk8, skeletal muscle actin 8. Results obtained using the geNorm and NormFinder algorithms showed high consistency, and differences in the activity of the selected actb with eif genes were successfully identified. The spring and autumn activities of the target genes (except ak) in the muscle tissue of males and females differed significantly, showing that both sexes are immensely involved in an array of breeding behaviors in spring, and females intensively recover in the autumn season. Characterization of first reference genes in spiny-cheek crayfish will facilitate more accurate and reliable expression studies in this key species.

scholarly journals Reference Gene Selection for Quantitative Real-Time RT-PCR Normalization inIris. lacteavar.chinensisRoots under Cadmium, Lead, and Salt Stress Conditions

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chun-Sun Gu ◽  
Liang-qin Liu ◽  
Chen Xu ◽  
Yan-hai Zhao ◽  
Xu-dong Zhu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Salt Stress ◽  
Real Time ◽  
Reference Genes ◽  
Elongation Factor ◽  
Stress Conditions ◽  
Translation Initiation Factor ◽  
Translation Elongation Factor ◽  
Translation Elongation ◽  
Wide Range

Quantitative real time PCR (RT-qPCR) has emerged as an accurate and sensitive method to measure the gene expression. However, obtaining reliable result depends on the selection of reference genes which normalize differences among samples. In this study, we assessed the expression stability of seven reference genes, namely, ubiquitin-protein ligase UBC9 (UBC), tubulin alpha-5 (TUBLIN), eukaryotic translation initiation factor (EIF-5A), translation elongation factor EF1A (EF1α), translation elongation factor EF1B (EF1b), actin11 (ACTIN), and histone H3 (HIS), inIris. lacteavar.chinensis(I. lacteavar.chinensis) root when the plants were subjected to cadmium (Cd), lead (Pb), and salt stress conditions. All seven reference genes showed a relatively wide range of threshold cycles (Ct) values in different samples. GeNorm and NormFinder algorithms were used to assess the suitable reference genes. The results from the two software units showed thatEIF-5AandUBCwere the most stable reference genes across all of the tested samples, whileTUBLINwas unsuitable as internal controls.I. lacteavar.chinensisis tolerant to Cd, Pb, and salt. Our results will benefit future research on gene expression in response to the three abiotic stresses.

Sign in / Sign up

Export Citation Format

Share Document