During cellular adaptation to low temperature, Escherichia coli transiently synthesizes the major cold-shock protein CspA. It was found that adaptation to cold shock is blocked when the 143-base sequence of the 5' untranslated region (5' UTR) of the cspA mRNA is overproduced. The overproduction of this UTR at 15 degrees C caused the synthesis of not only CspA but also other cold-shock proteins ...

Insulators play important roles in controlling gene activity and maintaining regulatory independence between neighbouring genes. In this article, we show that the enhancer-blocking activity of the insulator present within the LTR retrotransposon Idefix can be abolished if two copies of the region containing the insulator--specifically, the long terminal repeat (LTR)--are fused to the retrotrans...

As an important mode of suppressing gene expression, messenger RNAs containing an AU-rich element (ARE) in the 3' untranslated region are rapidly degraded in the cytoplasm. ARE-mediated mRNA decay (AMD) is initiated by deadenylation, and in vitro studies have indicated that subsequent degradation occurs in the 3'-5' direction through a complex of exonucleases termed the exosome. An alternative ...

RNA has long been a favoured medium for in vitro evolution and engineering. Functional RNAs produced in vitro can bind small molecules (aptamers), possess catalytic activity (ribozymes) or do both (aptazymes). A plethora of recent work has shown similar strategies used naturally for gene regulation in bacteria. Interest in these natural systems has inspired an effort to engineer and evolve this...

We have used the Escherichia coli beta-glucuronidase (uidA) gene as a reporter gene to localize the promoter and analyze the function of the 5' untranslated region (UTR) of the Chlamydomonas chloroplast petD gene. Using particle bombardment, petD-uidA transcriptional and translational fusion genes were introduced into the chloroplast genome in the large inverted repeat flanking the atpB gene. I...

Secondary structures within the 5' untranslated regions of messenger RNAs can have profound effects on the efficiency of translation of their messages and thereby on gene expression. Consequently they can act as important regulatory motifs in both physiological and pathological settings. Current approaches to predicting the secondary structure of these RNA sequences find the structure with the ...

Viral gene products are generally required in widely differing amounts for successful virus growth and assembly. For coronaviruses, regulation of transcription is a major contributor to these differences, but regulation of translation may also be important. Here, we examine the possibility that the 5' untranslated regions (UTRs), unique for each of the nine species of mRNA in the bovine coronav...

BACKGROUND AND OBJECTIVE The gene responsible for the P1 polymorphism of the P blood-group system remains unidentified, although the A4GALT gene, whose product is responsible for the production of P(k), has been implicated. No coding differences in A4GALT account for the P1 polymorphism, but homozygosity for two polymorphisms (-551_-550insC and -160A>G) in the 5' untranslated region of the gene...

In organelles, the posttranscriptional steps of gene expression are tightly controlled by nucleus-encoded factors, most often acting in a gene-specific manner. Despite the molecular identification of a growing number of factors, their mode of action remains largely unknown. In the green alga Chlamydomonas reinhardtii, expression of the chloroplast petA gene, which codes for cytochrome f, depend...

During investigations on the regulation of the Pax-6 gene, we characterized a cDNA from quail neuroretina showing a 5' untranslated region distinct from that previously described and initiated from an internal promoter. Using RNase protection and primer extension mapping, we localized this second quail Pax-6 promoter, termed P1. As reported for the already described P0 promoter, P1 was also tra...