Rare codons selectively limit the accumulation of Ras family member proteins with important consequences for Ras pathway activation and tumorigenesis.

Evolved codon usages often pose a technical challenge over the expressing of eukaryotic genes in microbial systems because of changed translational machinery. In the present study, we investigated the translational effects of intragenic differential codon usage on the expression of the new Drosophila gene, jingwei (jgw), a chimera derived from two unrelated parental genes: Ymp and Adh. We found...

Recently, artificial gene networks have been developed in synthetic biology to control gene expression and make organisms as controllable as robots. Here, I present an artificial posttranslational gene-silencing system based on the codon usage bias and low tRNA content corresponding to minor codons. I engineered the green fluorescent protein (GFP) gene to inhibit translation indirectly with the...

Initiation is often assumed to be rate-limiting for protein synthesis, but the presence of rare codons nonetheless can influence protein levels. In this issue of The EMBO Journal, Chu et al report that when rare codons are positioned near the start of the coding region, 'liberation' of the initiation codon for loading of the next 40S subunit may be rate‐limiting for initiation and therefore ove...

We report a novel fusion tag for expressing recombinant proteins in E. coli. The fusion tag is the C-terminus part of the human GMCSF gene comprising 45 amino acids, which aid in over expression of otherwise non expressible genes. Expression of hIFN 2b with this fusion tag also escapes the requirement of rare codons for expression. This is also a first report of a small fusion tag of human orig...

Rare codons generally arrest translation due to rarity of their cognate tRNAs. This property of rare codons can be utilized to regulate protein expression. In this study, a linear relationship was found between expression levels of genes and copy numbers of rare codons inserted within them. Based on this discovery, we constructed a molecular device in Escherichia coli using the rare codon AGG, ...

Engineering radically altered genetic codes will allow for genomically recoded organisms that have expanded chemical capabilities and are isolated from nature. We have previously reassigned the translation function of the UAG stop codon; however, reassigning sense codons poses a greater challenge because such codons are more prevalent, and their usage regulates gene expression in ways that are ...

AGA and AGG codons for arginine are the least used codons in Escherichia coli, which are encoded by a rare tRNA, the product of the dnaY gene. We examined the positions of arginine residues encoded by AGA/AGG codons in 678 E. coli proteins. It was found that AGA/AGG codons appear much more frequently within the first 25 codons. This tendency becomes more significant in those proteins containing...

Many clostridial proteins are poorly produced in Escherichia coli. It has been suggested that this phenomena is due to the fact that several types of codons common in clostridial coding sequences are rarely used in E. coli and the quantities of the corresponding tRNAs in E. coli are not sufficient to ensure efficient translation of the corresponding clostridial sequences. To address this issue,...