title: Molecular characterization of atrogin-1/F-box protein-32 (FBXO32) and F-box protein-25 (FBXO25) in rainbow trout (Oncorhynchus mykiss): Expression across tissues in response to feed deprivation.
abstract: The characteristic increase in protein catabolism during muscle atrophy is largely the result of an increase in E3 ubiquitin ligase expression, specifically that of atrogin-1, or FBXO32, which functions to polyubiquitinate proteins. In rainbow trout, the cDNA sequences of two E3 ubiquitin ligase F-box proteins, FBXO32 and FBXO25, were characterized and their expression across tissues in response to feed deprivation was determined. The cDNA sequence for FBXO32 encodes a protein 355 amino acids long and is 97% identical to the homologous protein in salmon, 85% to zebrafish and 72% identical to both human and mouse. The cDNA for FBXO25 encodes a protein 356 amino acids in length that is 98% identical to the homologous protein in salmon, 84% to zebrafish, and 75% to human. After 28days of feed deprivation, FBXO32 expression increased by approximately 13-fold, 3-fold, and 5-fold in white muscle, red muscle, and intestine, respectively (P<0.05). Expression of FBXO32 and FBXO25 in kidney decreased 0.3-fold and 0.2-fold, respectively, and FBXO25 expression decreased by 0.2-fold in liver (P<0.05). These results indicate that these protein sequences are conserved and suggest that the up-regulation of FBXO32 is associated with skeletal and smooth muscle atrophy that occurs during fasting.
authors.affiliation: USDA-ARS, National Center for Cool and Cold Water Aquaculture, 11861 Leetown Rd, Kearneysville, WV 25430, USA. beth.cleveland@ars.usda.gov
authors.forename: Beth M
authors.initials: BM
authors.lastname: Cleveland
authors.forename: Jason P
authors.initials: JP
authors.lastname: Evenhuis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D044783:F-Box Proteins / Q000235:genetics / Q000378:metabolism*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005508:Food Deprivation; D015870:Gene Expression; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D044843:SKP Cullin F-Box Protein Ligases / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014018:Tissue Distribution
chemical_list: D044783:F-Box Proteins; D029941:Fish Proteins; D044843:SKP Cullin F-Box Protein Ligases