Detection of sialoglycomolecules in five plant trypanosomatids and in an insect phytophagous isolate

A mutation in the cell division gene ftsK causes super-induction of sigma(70)-dependent stress defense genes, such as uspA, during entry of cells into stationary phase. In contrast, we report here that stationary phase induction of sigma(S)-dependent genes, uspB and cfa, is attenuated and that sigma(S) accumulates at a lower rate in ftsK1 cells. Ectopic overexpression of rpoS restored induction of the rpoS regulon in the ftsK mutant, as did a deletion in the recA gene. Thus, a mutation in the cell division gene, ftsK, uncouples the otherwise coordinated induction of sigma(S)-dependent genes and the universal stress response gene, uspA, during entry into stationary phase.     

MiR-34a inhibits lymphatic metastasis potential of mouse hepatoma cells

Genetic adaptation is one of the key features of Escherichia coli (E. coli) that ensure its survival in different hostile environments. E. coli seems to initiate biofilm development in response to specific environmental cues. A number of properties inherent within bacterial biofilms indicate that their gene expression is different from that of planktonic bacteria. Two of the possible important genes are rpoS and bolA. The rpoS gene has been known as the alternative sigma (σ) factor, which controls the expression of a large number of genes, which are involved in responses to a varied number of stresses, as well as transition to stationary phase from exponential form of growth. Morphogene bolA response to stress environment leads to round morphology of E. coli cells, but little is known about its involvement in biofilms and its development or maintenance. The purpose of this study was to understand and analyse the responses of rpoS and bolA gene to sudden change in the environment. In this study, E. coli K-12 MG1655, rpoS, and bolA mutant strains were used and gene expression was studied. Results show that both genes contribute to the ability to respond and adapt in response to various types of stresses. RpoS response to various stress environments was somehow constant in both the planktonic and biofilm phases, whereas bolA responded well under various stress conditions, in both planktonic and biofilm mode, up to 5-6-fold change in the expression was noticed in the case of pH variation and hydrogen peroxide stress (H(2)O(2)) as compared with rpoS.