Scientists have published work this week in PLoS Biology looking at genetic switches and gene expression related to cell fate. They used a "classic bistable memory module" to find transcription errors, using the lac operon in E. coli as a positive feedback loop. Using single cell analysis, they showed that when transcriptional fidelity decreases, the frequency of epigenetic switching from one state of expression to the other is increased.
Scientists have developed a Web-based tool, PPI Finder, to mine human protein-protein interactions from PubMed abstracts. Their work was published this week in PLoS One. They found that only 28 percent of the co-occurred pairs in PubMed abstracts appeared in human PPI databases (HPRD, BioGRID, and BIND). However, 69 percent of the known PPIs in HPRD showed co-occurrences in the literature, and 65 percent shared GO terms. It is freely accessble here.
Researchers have screened a 2,000-compound chemical library for inhibitors of infection of mammalian cells by Trypanosoma cruzi trypomastigotes. Using a recombinant T. cruzi expressing β-galactosidase, they chose three hits for their high activity against T. cruzi and low toxicity: PCH1, NT1, and CX1. "These results provide new candidate molecules for the development of treatments against Chagas disease and leishmaniasis," they write in the abstract in PLoS Neglected Tropical Diseases.
In work published in PLoS Pathogens, scientists have used quantitative metabolomics to compare siderophore production in E. coli between urinary and rectal cells within individual patients with recurrent UTI. While all strains produced enterobactin, preferential expression of the siderophores yersiniabactin and salmochelin occurred in urinary strains. "Because the virulence-associated biosynthetic pathways are distinct from those associated with rectal colonization, these results suggest strategies for virulence-targeted therapies," the authors say.