This study investigated the hypothesis that supplementation of methionine (Met) to broiler diets increases muscle growth due to regulation of molecular pathways related to protein synthesis and degradation depending on the Met source. Day-old male Cobb-500 broilers (n = 240) were phase-fed three different wheat-soya bean meal-based basal diets during days 1-10, 11-21 and 22-35. Basal diets (Met- group, Met + Cys concentration 15% below NRC recommendations) were supplemented with 0.10% or 0.40% Met either as DL-Met (DLM) or DL-2-hydroxy-4-(methylthio) butanoic acid (DL-HMTBA) (equimolar comparison). Breast muscle weights were lower in the Met- group compared to all Met-supplemented groups and were lower in broilers supplemented with 0.10% of DL-HMTBA compared to the other groups fed Met-supplemented diets. However, the expression of genes or relative phosphorylation and thus activation state of proteins involved in the somatotropic axis, the mammalian target of rapamycin (mTOR) pathway of protein synthesis, the ubiquitin-proteasome pathway (UPP) and autophagy-lysosomal pathway of protein degradation, the GCN2/eIF2a pathway involved in the inhibition of protein synthesis and in the myostatin-Smad2/3 pathway involved in myogenesis were not affected by Met source. Feeding diets with suboptimum Met + Cys concentrations, however, decreased expression of GHR and IGF1 in liver and muscle and increased that of MURF1 involved in the UPP in the broiler's muscle at day 10 and 21, while that of FOXO and atrogin-1 and FOXO phosphorylation remained unaffected. Additionally, suboptimum dietary Met concentrations increased expression of the autophagy-related genes ATG5 and BECN1 at day 35. Met supplementation neither affected gene expression nor phosphorylation of proteins involved in the GNC2/eIF2a and mTOR pathways. These data indicate that protein synthesis was not affected on the molecular level, while protein degradation was marginally affected by dietary Met dosage.
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http://dx.doi.org/10.1111/jpn.13026 | DOI Listing |
PLoS One
January 2025
Department of Cardiovascular and Metabolic Medicine, Faculty of Health and Life Sciences, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom.
Introduction: New Onset Atrial Fibrillation (NOAF) is the most common arrhythmia in intensive care. Complications of NOAF include thromboembolic events such as myocardial infarction and stroke, which contribute to a greater risk of mortality. Inflammatory and coagulation biomarkers in sepsis are thought to be associated with NOAF development.
View Article and Find Full Text PDFPLoS Biol
January 2025
Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
Ubiquitin-conjugating enzymes (E2s) are key for protein turnover and quality control via ubiquitination. Some E2s also physically interact with the proteasome, but it remains undetermined which E2s maintain proteostasis during aging. Here, we find that E2s have diverse roles in handling a model aggregation-prone protein (huntingtin-polyQ) in the Drosophila retina: while some E2s mediate aggregate assembly, UBE2D/effete (eff) and other E2s are required for huntingtin-polyQ degradation.
View Article and Find Full Text PDFElife
January 2025
Innovative Genomics Institute, University of California, Berkeley, Berkeley, United States.
Stem cell differentiation involves a global increase in protein synthesis to meet the demands of specialized cell types. However, the molecular mechanisms underlying this translational burst and the involvement of initiation factors remains largely unknown. Here, we investigate the role of eukaryotic initiation factor 3 (eIF3) in early differentiation of human pluripotent stem cell (hPSC)-derived neural progenitor cells (NPCs).
View Article and Find Full Text PDFMar Biotechnol (NY)
January 2025
Marine Ecology Research Center, Ministry of Natural Resources, First Institute of Oceanography, Qingdao, 266061, China.
Planiliza haematocheilus, a teleostan species noted for its ecological adaptability and economic significance, thrives in both freshwater and marine environments. This study presents a novel chromosome-level genome assembly through Hi-C, PacBio CCS, and Illumina sequencing methods. The assembled genome has a final size of 651.
View Article and Find Full Text PDFMol Biol Cell
January 2025
Department of Cell Biology, Emory University, 615 Michael St, Atlanta, GA, USA, 30322.
Rare inherited diseases caused by mutations in the copper transporters (CTR1) or induce copper deficiency in the brain, causing seizures and neurodegeneration in infancy through poorly understood mechanisms. Here, we used multiple model systems to characterize the molecular mechanisms by which neuronal cells respond to copper deficiency. Targeted deletion of CTR1 in neuroblastoma cells produced copper deficiency that produced a metabolic shift favoring glycolysis over oxidative phosphorylation.
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