An analysis of the influence of thyroid hormone on the synthesis of proteins in the tail fin of bullfrog tadpoles

Abstract

By incubation of explants of tail fin from tadpoles of Rana catesbeiana in a solution of 35S-methionine for 4 h, newly synthesized proteins were labeled isotopically. After separation by two-dimensional polyacrylamide gel electrophoresis, those proteins were visualized by fluorography. Exposure of explants to culture medium containing thyroxine (T4) (150 nM) increased the incorporation of 35S-methionine into several proteins with 48 h. Effects of T4 on the relative abundance of two of these newly synthesized proteins were detected after 8 h of hormonal treatment. Very similar patterns of newly synthesized proteins were observed when proteins from explants of tail fin removed from tadpoles at metamorphic climax and immediately incubated with 35S-methionine were compared with proteins produced in fin derived from premetamorphic animals. These results are interpreted to indicate that both treatment of explants with T4 and elevation of endogenous levels of thyroid hormones during spontaneous metamorphosis increased the relative rates of synthesis of several identical proteins. The potential involvement of those proteins in early phases of metamorphic action which eventually lead to cell death and resorption is discussed.

Analysis of the Rana catesbeiana tadpole tail fin proteome and phosphoproteome during T3-induced apoptosis: identification of a novel type I keratin

“…Proteomic scale studies on TH-dependent tail regression have been scarce. Ray et al identified several 35 S-methionine labelled proteins from Rana catesbeiana tail fin that change during natural and precocious metamorphosis using two-dimensional (2D) gel analysis [ 17 ]. Kobayashi et al used 2D gel electrophoresis to analyze changes in protein expression in the back and tail skin of Xenopus laevis during metamorphosis [ 18 ].…”

Metabolic Action of Thyroid Hormones: Insights from Functional and Proteomic Studies

“…Domanski and Helbing (2007), in the field of amphibian metamorphosis, went through proteomics to study the relationship between the most well established transcriptomic events involved in tail regression and the changes in the proteome also in view of non-classical THs action trough phosphorylation signalling pathways. Following previous proteomic scale studies in the field (Ray and Dent, 1986;Kobayashi et al, 1996;Helbing et al, 2003), the authors (Domanski and Helbing, 2007), by means of two-dimentional gel electrophoresis and phosphoprotein-specific stain, identified novel changes in the proteome and phosphoproteome associated with the induction of T3-dependent tail regression of Rana catesbeiana tadpoles. They identified, in particular, a novel keratin that is a target for T3-mediated changes in the tail that can serve as an indicator of early response to this hormone.…”