Bone marrow niches in myelodysplastic syndromes.

Genetic and epigenetic lesions within hematopoietic cell populations drive diverse hematological malignancies. Myelodysplastic syndromes (MDS) are a group of myeloid neoplasms affecting the hematopoietic stem cells characterized by recurrent genetic abnormalities, myelodysplasia (a pathological definition of abnormal bone marrow structure), ineffective hematopoiesis resulting in blood cytopenia, and a propensity to evolve into acute myelogenous leukemia. Although there is evidence that the accumulation of a set of genetic mutations is an essential event in MDS, there is an increased appreciation of the contribution of specific microenvironments, niches, in the pathogenesis of MDS and response to treatment.

Identification of BvgA-Dependent and BvgA-Independent Small RNAs (sRNAs) in Bordetella pertussis Using the Prokaryotic sRNA Prediction Toolkit ANNOgesic.

Noncoding small RNAs (sRNAs) are crucial for the posttranscriptional regulation of gene expression in all organisms and are known to be involved in the regulation of bacterial virulence. In the human pathogen Bordetella pertussis, which causes whooping cough, virulence is controlled primarily by the master two-component system BvgA (response regulator)/BvgS (sensor kinase). In this system, BvgA is phosphorylated (Bvg mode) or nonphosphorylated (Bvg mode), with global transcriptional differences between the two.

The coordinated action of RNase III and RNase G controls enolase expression in response to oxygen availability in Escherichia coli.

Rapid modulation of RNA function by endoribonucleases during physiological responses to environmental changes is known to be an effective bacterial biochemical adaptation. We report a molecular mechanism underlying the regulation of enolase (eno) expression by two endoribonucleases, RNase G and RNase III, the expression levels of which are modulated by oxygen availability in Escherichia coli. Analyses of transcriptional eno-cat fusion constructs strongly suggested the existence of cis-acting elements in the eno 5' untranslated region that respond to RNase III and RNase G cellular concentrations.

The effect of electron density in furan pendant group on thermal-reversible Diels-Alder reaction based self-healing properties of polymethacrylate derivatives.

Herein, we discuss the effect of electron density in a furan pendant group on the thermally reversible Diels-Alder (DA) reaction based self-healing efficiency in polymethacrylate derivatives. First, the furan-functionalized polymethacrylates (rPFMA and dPFMA) having different electron density in the furan pendant groups were prepared through free-radical polymerization. The healing efficiency of rPFMA, which was expected to have high healing efficiency due to the high reactivity of DA reaction originating from the electron density in the furan moiety, was shown to be 95.

Regulation of Escherichia coli RNase III activity.

Bacterial cells respond to changes in the environment by adjusting their physiological reactions. In cascades of cellular responses to stresses of various origins, rapid modulation of RNA function is known to be an effective biochemical adaptation. Among many factors affecting RNA function, RNase III, a member of the phylogenetically highly conserved endoribonuclease III family, plays a key role in posttranscriptional regulatory pathways in Escherichia coli.

Two tandem RNase III cleavage sites determine betT mRNA stability in response to osmotic stress in Escherichia coli.

While identifying genes regulated by ribonuclease III (RNase III) in Escherichia coli, we observed that steady-state levels of betT mRNA, which encodes a transporter mediating the influx of choline, are dependent on cellular concentrations of RNase III. In the present study, we also observed that steady-state levels of betT mRNA are dependent on RNase III activity upon exposure to osmotic stress, indicating the presence of cis-acting elements controlled by RNase III in betT mRNA. Primer extension analyses of betT mRNA revealed two tandem RNase III cleavage sites in its stem-loop region, which were biochemically confirmed via in vitro cleavage assays.

RNase III controls mltD mRNA degradation in Escherichia coli.

RNase III is a double-stranded RNA-specific endoribonuclease that processes and degrades numerous mRNA molecules in Escherichia coli. A previous genome-wide analysis of E. coli transcripts showed that steady-state levels of mltD mRNA, which encodes membrane-bound lytic murein transglycosylase D, was most affected by changes in cellular concentration of RNase III.

RNase III controls the degradation of corA mRNA in Escherichia coli.

In Escherichia coli, the corA gene encodes a transporter that mediates the influx of Co(2+), Mg(2+), and Ni(2+) into the cell. During the course of experiments aimed at identifying RNase III-dependent genes in E. coli, we observed that steady-state levels of corA mRNA as well as the degree of cobalt influx into the cell were dependent on cellular concentrations of RNase III.