scholarly journals Dynamic regulation of N6,2′-O-dimethyladenosine (m6Am) in obesity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Moshe Shay Ben-Haim ◽  
Yishay Pinto ◽  
Sharon Moshitch-Moshkovitz ◽  
Vera Hershkovitz ◽  
Nitzan Kol ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Translation Regulation ◽  
Fatty Acid Binding Proteins ◽  
Translation Efficiency ◽  
High Fat ◽  
Human Obesity ◽  
Dynamic Regulation ◽  
Fatty Acid Binding ◽  
Obesity Gene ◽  
Protein Levels

AbstractThe prevalent m6Am mRNA cap modification was recently identified as a valid target for removal by the human obesity gene FTO along with the previously established m6A mRNA modification. However, the deposition and dynamics of m6Am in regulating obesity are unknown. Here, we investigate the liver m6A/m methylomes in mice fed on a high fat Western-diet and in ob/ob mice. We find that FTO levels are elevated in fat mice, and that genes which lost m6Am marking under obesity are overly downregulated, including the two fatty-acid-binding proteins FABP2, and FABP5. Furthermore, the cellular perturbation of FTO correspondingly affect protein levels of its targets. Notably, generally m6Am- but not m6A-methylated genes, are found to be highly enriched in metabolic processes. Finally, we deplete all m6A background via Mettl3 knockout, and unequivocally uncover the association of m6Am methylation with increased mRNA stability, translation efficiency, and higher protein expression. Together, these results strongly implicate a dynamic role for m6Am in obesity-related translation regulation.

scholarly journals Actively translated uORFs reduce translation and mRNA stability independent of NMD in Arabidopsis

2021 ◽  
Author(s):  
Hsin-Yen Larry Wu ◽  
Polly Yingshan Hsu
Keyword(s):  
Gene Expression ◽  
Mrna Stability ◽  
Gene Expression Regulation ◽  
Regulatory Elements ◽  
Expression Regulation ◽  
Ribosome Profiling ◽  
Translation Efficiency ◽  
Nonsense Mediated Decay ◽  
Protein Levels ◽  
Eukaryotic Genes

ABSTRACTUpstream ORFs (uORFs) are widespread cis-regulatory elements in the 5’ untranslated regions of eukaryotic genes. Translation of uORFs could negatively regulate protein synthesis by repressing main ORF (mORF) translation and by reducing mRNA stability presumably through nonsense-mediated decay (NMD). While the above expectations were supported in animals, they have not been extensively tested in plants. Using ribosome profiling, we systematically identified 2093 Actively Translated uORFs (ATuORFs) in Arabidopsis seedlings and examined their roles in gene expression regulation by integrating multiple genome-wide datasets. Compared with genes without uORFs, we found ATuORFs result in 38%, 14%, and 43% reductions in translation efficiency, mRNA stability, and protein levels, respectively. The effects of predicted but not actively translated uORFs are much weaker than those of ATuORFs. Interestingly, ATuORF-containing genes are also expressed at higher levels and encode longer proteins with conserved domains, features that are common in evolutionarily older genes. Moreover, we provide evidence that uORF translation in plants, unlike in vertebrates, generally does not trigger NMD. We found ATuORF-containing transcripts are degraded through 5’ to 3’ decay, while NMD targets are degraded through both 5’ to 3’ and 3’ to 5’ decay, suggesting uORF-associated mRNA decay and NMD have distinct genetic requirements. Furthermore, we showed ATuORFs and NMD repress translation through separate mechanisms. Our results reveal that the potent inhibition of uORFs on mORF translation and mRNA stability in plants are independent of NMD, highlighting a fundamental difference in gene expression regulation by uORFs in the plant and animal kingdoms.

scholarly journals Direct Comparison of Mice Null for Liver or Intestinal Fatty Acid-binding Proteins Reveals Highly Divergent Phenotypic Responses to High Fat Feeding

2013 ◽  
Vol 288 (42) ◽  
pp. 30330-30344 ◽  
Author(s):  
Angela M. Gajda ◽  
Yin Xiu Zhou ◽  
Luis B. Agellon ◽  
Susan K. Fried ◽  
Sarala Kodukula ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Binding Proteins ◽  
Fatty Acid Binding Proteins ◽  
High Fat ◽  
Fatty Acid Binding ◽  
Fat Feeding ◽  
Phenotypic Responses

scholarly journals Fatty acid transfer between multilamellar liposomes and fatty acid-binding proteins.

1984 ◽  
Vol 259 (21) ◽  
pp. 13395-13401 ◽  
Author(s):  
P Brecher ◽  
R Saouaf ◽  
J M Sugarman ◽  
D Eisenberg ◽  
K LaRosa
Keyword(s):  
Fatty Acid ◽  
Binding Proteins ◽  
Fatty Acid Binding Proteins ◽  
Fatty Acid Binding ◽  
Multilamellar Liposomes

scholarly journals Increased Levels of Adipocyte and Epidermal Fatty Acid-Binding Proteins in Acute Lymphoblastic Leukemia Survivors

2021 ◽  
Vol 10 (8) ◽  
pp. 1567
Author(s):  
Katarzyna Konończuk ◽  
Eryk Latoch ◽  
Beata Żelazowska-Rutkowska ◽  
Maryna Krawczuk-Rybak ◽  
Katarzyna Muszyńska-Rosłan
Keyword(s):  
Metabolic Syndrome ◽  
Fatty Acid ◽  
Acute Lymphoblastic Leukemia ◽  
Binding Proteins ◽  
Lymphoblastic Leukemia ◽  
Fatty Acid Binding Proteins ◽  
Fatty Acid Binding ◽  
The Metabolic Syndrome ◽  
Increased Risk ◽  
Significant Difference

Childhood cancer survivors are highly exposed to the development of side effects after many years of cessation of anticancer treatment, including altered lipid metabolism that may result in an increased risk of overweight and metabolic syndrome. Adipocyte (A-FABP) and epidermal (E-FABP) fatty acid-binding proteins are expressed in adipocytes and are assumed to play an important role in the development of lipid disturbances leading to the onset of metabolic syndrome. The aim of this study was to investigate the association between serum A-FABP and E-FABP levels, overweight, and components of the metabolic syndrome in acute lymphoblastic leukemia survivors. Sixty-two acute lymphoblastic leukemia (ALL) survivors (34 females) were included in the study. The mean age at the time of the study was 12.41 ± 4.98 years (range 4.71–23.43). Serum levels of A-FABP and E-FABP were analyzed using a commercially available ELISA kit. The ALL survivors presented statistically higher A-FABP levels in comparison with the healthy controls (25.57 ± 14.46 vs. 15.13 ± 7.61 ng/mL, p < 0.001). The subjects with body mass index (BMI) above the normal range (18 overweight, 10 obese) had a greater level of A-FABP compared to the ALL group with normal BMI (32.02 ± 17.10 vs. 20.33 ± 9.24 ng/mL, p = 0.006). Of all participants, 53.23% had at least one risk factor of metabolic syndrome; in this group, only the A-FABP level showed a statistically significant difference compared to the healthy control group (30.63 ± 15.91 vs. 15.13 ± 7.61 ng/mL, p < 0.001). The subjects with two or more metabolic risk factors (16.13%) presented higher levels of both A-FABP (33.62 ± 17.16 vs. 15.13 ± 7.61 ng/mL, p = 0.001) and E-FABP (13.37 ± 3.62 vs. 10.12 ± 3.21 ng/mL, p = 0.021) compared to the controls. Univariable regression models showed significant associations between BMI and systolic blood pressure with the A-FABP level (coeff. 1.02 and 13.74, respectively; p < 0.05). In contrast, the E-FABP level was only affected by BMI (coeff. 0.48; p < 0.01). The findings reported herein suggest that the increased levels of A-FABP and E-FABP may be involved in the pathogenesis of overweight and the onset of metabolic syndrome in acute lymphoblastic leukemia. However, further longitudinal, prospective studies of fatty acid-binding proteins and their potential role in the pathogenesis of obesity and metabolic syndrome in ALL survivors remain to be performed.

scholarly journals m5U54 tRNA Hypomodification by Lack of TRMT2A Drives the Generation of tRNA-Derived Small RNAs

2021 ◽  
Vol 22 (6) ◽  
pp. 2941
Author(s):  
Marisa Pereira ◽  
Diana R. Ribeiro ◽  
Miguel M. Pinheiro ◽  
Margarida Ferreira ◽  
Stefanie Kellner ◽  
...  
Keyword(s):  
Stress Response ◽  
Small Rnas ◽  
Mammalian Cells ◽  
Cellular Stress ◽  
Cellular Stress Response ◽  
Translation Regulation ◽  
Translation Efficiency ◽  
Down Regulation ◽  
Gene Expression Control ◽  
The Impact

Transfer RNA (tRNA) molecules contain various post-transcriptional modifications that are crucial for tRNA stability, translation efficiency, and fidelity. Besides their canonical roles in translation, tRNAs also originate tRNA-derived small RNAs (tsRNAs), a class of small non-coding RNAs with regulatory functions ranging from translation regulation to gene expression control and cellular stress response. Recent evidence indicates that tsRNAs are also modified, however, the impact of tRNA epitranscriptome deregulation on tsRNAs generation is only now beginning to be uncovered. The 5-methyluridine (m5U) modification at position 54 of cytosolic tRNAs is one of the most common and conserved tRNA modifications among species. The tRNA methyltransferase TRMT2A catalyzes this modification, but its biological role remains mostly unexplored. Here, we show that TRMT2A knockdown in human cells induces m5U54 tRNA hypomodification and tsRNA formation. More specifically, m5U54 hypomodification is followed by overexpression of the ribonuclease angiogenin (ANG) that cleaves tRNAs near the anticodon, resulting in accumulation of 5′tRNA-derived stress-induced RNAs (5′tiRNAs), namely 5′tiRNA-GlyGCC and 5′tiRNA-GluCTC, among others. Additionally, transcriptomic analysis confirms that down-regulation of TRMT2A and consequently m5U54 hypomodification impacts the cellular stress response and RNA stability, which is often correlated with tiRNA generation. Accordingly, exposure to oxidative stress conditions induces TRMT2A down-regulation and tiRNA formation in mammalian cells. These results establish a link between tRNA hypomethylation and ANG-dependent tsRNAs formation and unravel m5U54 as a tRNA cleavage protective mark.

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