Translational Regulation of Gene Expression

Given the accelerated growth of knowledge in the field of gene expression, it seemed timely to discuss current developments in the area of translational reg ulation of gene expression as well as to evaluate emerging technology. Translational regulation occurs with prokaryotic as well as with eukaryotic messenger RNA (mRNA) in vivo and in vitro. In prokaryotes, through genetic manipulations and mutagenesis, the mechanisms are much better understood, as for example the mechanism of attenuation. In bacteria, different translational efficiencies for the same mRNA may vary by lOOO-fold. Translational regulation was first observed in 1966 with RNA phages of Escherichia coli by Lodish and Zinder. However, translational regulation of proteins from DNA genomes is also well described for bacteria, as for example gene 32 protein of bacteriophage T4 and E. coli ribosomal proteins. In eukaryotes, the utilization of an individual mRNA species with different efficiencies is poorly understood. For example, mRNA for ribosomal proteins is translationally regulated during Drosophila oogenesis, without any clue to the mechanism involved. It was observed that ribosomal protein mRNA during Drosophila oogenesis and embryogenesis is selectively on or off the polysomes during different developmental stages. In contrast, bacterial ribosomal protein is also translationally regulated by autogenous regulation. The mechanism is well understood and involves binding of the gene product to its transcript in competition with rRNA.

Inhalt
1 Translational Regulation of Ribosomal Proteins in Escherichia coli: Molecular Mechanisms.- 2 Translational Regulation in Bacteriophages.- 3 Escherichia coli Threonyl-Transfer RNA Synthetase as a Model System to Study Translational Autoregulation in Prokaryotes.- 4 Translational Regulation of Ribosomal Protein Gene Expression in Eukaryotes.- 5 Selective Messenger RNA Translation in Marine Invertebrate Oocytes, Eggs, and Zygotes.- 6 Molecular Mechanisms of Translational Control during the Early Development of Xenopus laevis.- 7 Storage and Translation of Ferritin Messenger RNA.- 8 Regulation of Messenger RNA Translation at the Elongation Step during Estradiol-Induced Vitellogenin Synthesis in Avian Liver.- 9 Translational Regulation in the Heat-Shock Response of Drosophila Cells.- 10 Strategies of Fibroin Production.- 11 Translational Regulation during Photomorphogenesis.- 12 Gene Expression in Muscle: The Role of Small RNAs in the Expression of Muscle-Specific Proteins.- 13 Involvement of Nucleotides in Protein Synthesis Initiation.- 14 Roles of Eukaryotic Initiation Factor 2 and Eukaryotic Initiation Factor 2 Ancillary Protein Factors in Eukaryotic Protein Synthesis Initiation.- 15 Role of Eukaryotic Messenger RNA Cap-Binding Protein in Regulation of Translation.- 16 Differential Translation of Eukaryotic Messenger RNAs: The Role of Messenger RNA Secondary Structure.- 17 Translational and Nontranslational Mechanisms of Regulation by Eukaryotic Suppressor Mutants.- 18 Translational Control of a Transcriptional Activator in the Regulation of Amino Acid Biosynthesis in Yeast.- 19 The Role of Messenger RNA Sequences and Structures in Eukaryotic Translation.- 20 Translational Regulation by Adenovirus Virus-Associated I RNA.- 21 Translational Control of Transcription Termination in Prokaryotes.