Translational rate

De Benedetti, A., Joshi-Barve, S., Rinker-Schaeffer, C., and Rhoads, R. E. (1991). Expression of antisense RNA against initiation factor eIF-4E mRNA in HeLa cells results in lengthened cell division times, diminished translation rates, and reduced levels of both eIF-4E and the p220 component of eIF-4F. Mol. Cell Biol. 11, 5435-5445. 

Hershey, J. W. B., Protein phosphorylation controls translation rates. J. Biol. Chem. 264 20823, 1989. Describes how protein kinases are thought to regulate translation in eukaryotic systems. 

Kondratiev, V. N. Holtschlag, L. J., Translator Rate Constants of Gas Phase Reactions, Reference Book Fristrom, R. M. Ed. Office of Standard Reference Data, National Bureau of Standards, U. S. Department of Commerce Washington, D. 

TRANSCRIPTION AND TRANSLATION RATES FOR hE AND IE STEPS IN METABOLIC PATHWAYS... 

Hershey JWB. Protein phosphorylation controls translation rates. J Biol Chem 264 20823-20826, 1989. 

Iron regulatory proteins (IRPs) regulate the cellular iron level in mammalian cells. IRPs are known as cytosol mRNA binding proteins which control the stability or the translation rate of mRNAs of iron metabolism-related proteins such as TfR, ferritin, and 5-aminolevulinic acid synthetase in response to the availability of cellular iron [19-21] after uptake [5]. The regulatory mechanism involves the interaction between the iron-responsive element (IRE) in the 3 or 5 untranslated regions of the transcripts and cytosolic IRPs (IRP-1 and -2). IRP-1 is an iron-sulfur (Fe-S) protein with aconitase activity containing a cubane 4Fe-4S cluster. When Fe is replete, IRP-1 prevails in a 4Fe-4S form as a holo-form and is an active cytoplasmic aconitase. As shown in Fig. 3, when Fe is deplete, it readily loses one Fe from the fourth labile Fe in the Fe-S cluster to become a 3Fe-4S cluster and in this state has little enzymatic activity [22, 23]. 

In the following, and for the sake of simplicity, the vertical translation rate of the solid in the liquid is supposed to be infinitely slow. Then, if the origin of the weight measurements is taken as the weight of the solid in the gas, the force f exerted on a solid partially immersed in a liquid, whose base is located at a level zb with respect to the flat horizontal surface of the liquid, is equal to the sum of the weight of the meniscus wm and the buoyancy force ... 

Figure 3.17. Common shape of an experimental curve of variations in the force exerted on a cylindrical solid during its immersion-emersion in a non-wetting liquid plotted as a function of the depth of immersion of the solid. The translation rate of the solid is supposed to be infinitely slow. From...

Until now, the translation rate of the solid has been considered to be infinitely slow. In practice, the contact angle measured during an immersion-emersion cycle... 

In addition to not addressing the need for individual tumbling rate constants for radical pair combinations leading to 3b, 2-BN, and 4-BN, Scheme 13.5 does not take into account the fact the values of probably differ and the translational rate constants definitely differ within amorphous and interfacial cages of either LDPE or HDPE. 

On the basis of the price levels as of spring 1979 and at the translation rate of 200 yen to one dollar, the construction cost of the Dry Process PUROX System in Japan is estimated to be about 13,000,000 for a 200 Mg/d facility ( 65,000 for Mg of refuse), exclusive of the land, utility supply facilities down to the battery limits, and fixtures and supplies. This is about 10% higher than the construction cost in Japan of the stoker incinerator, which is estimated to be about 58,500 per Mg of refuse. 

In our laboratory, reduced temperature at induction is the first thing attempted to increase the solubility of an expressed protein. Frequently, reducing the induction temperature from 37 to 15—20 °C can change the solubility level of an overproduced protein from undetectable to adequate.82 Reduced temperature slows both transcription and translation rates and reduces the strength of hydrophobic interactions. However, below 15 °C many promoter systems are inefficient. For these very low temperatures, use of cold-inducible promoters can be advantageous as most commonly used promoter systems work with reduced efficiency at decreased temperatures.83-85 Systems based on the promoter from the major E. coli cold-shock gene cspA have been described and have demonstrated their utility with membrane-associated proteins as well as those prone to proteolysis.86,87... 

There is indirect evidence for the existence of an SRP-like entity in E. coli. Pagds et al. (1985) have presented preliminary findings that indicate that a translation block may occur during the synthesis of pre-PhoS, a periplasmic phosphate-binding protein. It is known that the translation rate in E. coli is nonuniform. Pause sites (Pag s et al., 1985) occur at codons complementary to uncommon tRNAs. However, a pause site in PhoS elongation corresponding to a peptide of 8 kDa is not accounted for by the presence of such codons. This peptide was subsequently con-... 

The simplest model for gene dynamics is the Hargrove-Schmidt model (Figure 18.2). The Hargrove-Schmidt model is a two-compartment model that assumes information flow from mRNA (M) to protein (P) via a first-order translation rate constant, kj, and independent, first-order degradation of mRNA and protein with rate constants ku and kp, respectively. The system is described by the differential equations and schematic in Figure 18.3. 

A synergism between IAA and BR was also described by Katsumi (72) in green cucumber hypocotyl segments, and analysis by the PEST program showed the difference between data sets for IAA alone and IAA with fixed concentrations of BR can be accounted for by a change in the parameter RAMP, suggesting that the response capacity of the tissue to IAA is enhanced by BR (8). Possible explanations for this effect could be increased numbers of receptors for IAA, amplification of the LAA-induced signal, or its transmission, increased transcription or translation rates for LAA-induced protein synthesis, decreased turnover of mRNA or proteins, increased rates of delivery of cell wall components, etc. Much more research is needed to examine these possibilities. 

The major differences between prokaryotic and eukaryotic translation control mechanisms are related to the complexity of eukaryotic gene expression. Features that distinguish eukaryotic translation include mRNA export (spatial separation of transcription and translation), mRNA stability (the half-lives of mRNA can be modulated), negative translational control (the translation of certain mRNAs can be blocked by the binding of specific repressor proteins), initiation factor phosphorylation (mRNA translation rates are altered by certain circumstances when eIF-2 is phosphorylated), and translational frame-shifting (certain mRNAs can be frame-shifted so that a different polypeptide is synthesized). 

That deregulation in nitrate reductase gene expression could possibly have been due to a modified transcription rate for the nitrate reductase gene or a modified translation rate for nitrate reductase mRNA, or it could have been due to interference with nitrate reduction, which could have limited reduced N metabolites to low levels. Further studies are needed to examine these possibilities. 

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