The Effect of Trna Concentration on the Rate of Protein Synthesis

Abstract

Abstract.-Two in vitro protein-synthesizing systems derived from E. coli have been utilized to demonstrate that the concentration of a tRNA species can regulate the rate of translation of a messenger RNA. (a) The rate of poly-U-directed C'4-phenylalanine incorporation into protein is stimulated by concentrations of tRNA"56 from 1.5 X 10-8 M to 3.0 X 10-6 M, the latter representing a tRNAPhe/70S ribosome ratio of 7. (b) Components of poly U system: Ribosomes from log phase E. coli W3100 were stirred for 18 hr in 0.01 M MgC12, 0.5 M NH4Cl, 0.01 M Tris-Cl, pH 7.6; they were then resuspended and centrifuged twice more in the same buffer.24 The final pellet was dialyzed 566

Factors controlling aminoacyl-transfer-ribonucleic acid synthesis in vitro by a plant system

“…Studies with microbial systems (Marshall & Zamecnik, 1969 Kosakowski, Neidhardt & Bock, 1970;Cole & Schimmel, 1970) have demonstrated good reaction rates in vitro. Similarly, the studies by Rubin, Kelmers & Goldstein (1967), Loftfield & Eigner (1968), Anderson (1969), Shearn & Horowitz (1969), Mehler (1970) and others, have clearly shown controlling effects of many factors on aminoacyl-tRNA synthesis.…”

“…10) and the differential effects of pH on individual amino acids suggest the probability that pH may function as a control factor during protein synthesis through its effect on aminoacylation of tRNA. This could be particularly effective if the aminoacylation of tRNA species corresponding to 'regulation codons' (Anderson, 1969), present in rate-limiting amounts, were highly pH-sensitive. Such systems could be particularly valuable in highly organized tissues, especially in higher-plant cells where the localization of intermediary metabolites and hence of pH within the cell is well established (MacLennan, Beevers & Harley, 1963;Oaks & Bidwell, 1970).…”

“…Henshall & Goodwin (1964) indicated that the activity of the aminoacyl-tRNA synthetase was a limiting factor, and the involvement of tRNA species in the control of protein synthesis has been studied in detail (Stent, 1964; Anderson, 1969;Sueoka & KanoSueoka, 1970). It is therefore apparent that an understanding of the conditions affecting aminoacyl-tRNA formation is essential to cell-free investigations on the mechanism of protein synthesis.…”

Conservation of the relative tRNA composition in healthy and cancerous tissues

“…Furthermore, codon usage in different genes tends to be related to their expression levels (Marais and Duret 2001;dos Reis et al 2004;Plotkin and Kudla 2010;Tuller et al 2010b). Specifically, highly expressed genes (e.g., ribosomal proteins) usually include codons that are recognized by more abundant tRNA molecules, suggesting that the control of the translation process is under selective pressure (Anderson 1969;Bulmer 1987).…”

Cell line‐specific control of recombinant monoclonal antibody production by CHO cells

“…A significant determining factor could (again) be codon use-bias within the ORF since not all isoaccepting tRNAs within cells are present at equal concentrations (Post and Nomura, 1980). The use of codons within the ORF that correspond to isoaccepting tRNA molecules in relatively low abundance can significantly slow the rate of translation (Anderson, 1969). Indeed, alteration of Mab genes to a human codon use bias has previously been shown to have a significant positive impact on recombinant Mab production by mammalian cells (Carton et al, 2007).…”