Transfer RNA modifications that alter +1 frameshifting in general fail to affect -1 frameshifting

Using mutants (tgt, mnmA(asuE, trmU), mnmE(trmE), miaA, miaB, miaE, truA(hisT), truB) of either Escherichia coli or Salmonella enterica serovar Typhimurium and the trm5 mutant of Saccharomyces cerevisiae, we have analyzed the influence by the modified nucleosides Q34, mnm(5)s(2)U34, ms(2)io(6)A37, Psi39, Psi55, m(1)G37, and yW37 on -1 frameshifts errors at various heptameric sequences, at which at least one codon is decoded by tRNAs having these modified nucleosides. The frequency of -1 frameshifting was the same in congenic strains only differing in the allelic state of the various tRNA modification genes. In fact, in one case (deficiency of mnm(5)s(2)U34), we observed a reduced ability of the undermodified tRNA to make a -1 frameshift error. These results are in sharp contrast to earlier observations that tRNA modification prevents +1 frameshifting suggesting that the mechanisms by which -1 and +1 frameshift errors occur are different. Possible mechanisms explaining these results are discussed.     

The cell cycle associated protein, HTm4, is expressed in differentiating cellsof the hematopoietic and central nervous system in mice

HTm4 is a member of a newly defined family of human and murine proteins, the MS4 (membrane-spanning four) protein group, which has a distinctive four-transmembrane structure. MS4 protein functions include roles as cell surface signaling receptors and intracellular adapter proteins. We have previously demonstrated that HTm4 regulates the function of the KAP phosphatase, a key regulator of cell cycle progression. In humans, the expression of HTm4 is largely restricted to cells of the hematopoietic lineage, possibly reflecting a causal role for this molecule in differentiation/proliferation of hematopoietic lineage cells. In this study, we show that, like the human homologue, murine HTm4 is also predominantly a hematopoietic protein with distinctive expression patterns in developing murine embryos and in adult animals. In addition, we observed that murine HTm4 is highly expressed in the developing and adult murine nervous system, suggesting a previously unrecognized role in central and peripheral nervous system development.JLK and XY contributed equally to this work     

Defining Th1 and Th2 immune responses in a reciprocal cytokine environment in vivo

The ability of committed Th1 and Th2 cells to function in altered cytokine environments is a central issue in autoimmune and immune-mediated diseases. Therefore, it is of interest to study the ability of Th1 or Th2 cells to expand and produce cytokine reciprocal environments in vivo. Using STAT4- and STAT6-deficient mice, we studied the expansion and cytokine production of Ag-specific Th1 or Th2 cells after transfer into Th1, Th2, or wild-type recipients. Our data show that these Th1 or Th2 cells proliferated and clonally expanded normally, regardless of the in vivo cytokine environment. These data have implications for the treatment of immune-mediated diseases by immunomodulatory agents that alter the cytokine milieu in vivo.     

Expression of a deregulated tobacco nitrate reductase gene in potato increases biomass production and decreases nitrate concentration in all organs

We investigated the physiological consequences for nitrogen metabolism and growth of the deregulated expression of an N-terminal-deleted tobacco nitrate reductase in two lines of potato (Solanum tuberosum L. cv Safrane). The transgenic plants showed a higher biomass accumulation, especially in tubers, but a constant nitrogen content per plant. This implies that the transformed lines had a reduced nitrogen concentration per unit of dry weight. A severe reduction in nitrate concentrations was also observed in all organs, but was more apparent in tubers where nitrate was almost undetectable in the transgenic lines. In leaves and roots, but not tubers, this nitrate decrease was accompanied by a statistically significant increase in the level of malate, which acts as a counter-anion for nitrate reduction. Apart from glutamine in tubers, no major changes in amino acid concentration were seen in leaves, roots or tubers. We conclude that enhancement of nitrate reduction rate leads to higher biomass production, probably by allowing a better allocation of N-resources to photosynthesis and C-metabolism.Abbreviations DAP Days after planting - Gln Glutamine - NR Nitrate reductase - WT Wild type     

Expression of AmphiCoe, an amphioxus COE/EBF gene, in the developing central nervous system and epidermal sensory neurons

The COE/EBF gene family marks a subset of prospective neurons in the vertebrate central and peripheral nervous system, including neurons deriving from some ectodermal placodes. Since placodes are often considered unique to vertebrates, we have characterised an amphioxus COE/EBF gene with the aim of using it as a marker to examine the timing and location of peripheral neuron differentiation. A single COE/EBF family member, AmphiCoe, was isolated from the amphioxus Branchiostoma floridae. AmphiCoe lies basal to the vertebrate COE/EBF genes in molecular phylogenetic analysis, suggesting that the duplications that formed the vertebrate COE/EBF family were specific to the vertebrate lineage. AmphiCoe is expressed in the central nervous system and in a small number of scattered ectodermal cells on the flanks of neurulae stage embryos. These cells become at least largely recessed beneath the ectoderm. Scanning electron microscopy was used to examine embryos in which the ectoderm had been partially peeled away. This revealed that these cells have neuronal morphology, and we infer that they are the precursors of epidermal primary sensory neurons. These characters lead us to suggest that differentiation of some ectodermal cells into sensory neurons with a tendency to sink beneath the embryonic surface represents a primitive feature that has become incorporated into placodes during vertebrate evolution.     

Effects of local protein stability and the geometric position of the substrate degradation tag on the efficiency of ClpXP denaturation and degradation

ClpX and related AAA+ ATPases of the Clp/Hsp100 family are able to denature native proteins. Here, we explore the role of protein stability in ClpX denaturation and subsequent ClpP degradation of model substrates bearing ssrA degradation tags at different positions. ClpXP degraded T. thermophilus RNase-H* with a C-terminal ssrA tag very efficiently, despite the very high global stability of this thermophilic protein. In fact, global thermodynamic stability appears to play little role in susceptibility to degradation, as a far less stable RNase-H*-ssrA mutant was degraded more slowly than wild type by ClpXP and a completely unfolded mutant variant was degraded less than twice as fast as the wild-type parent. When ssrA peptide tags were covalently linked to surface cysteines at positions 114 or 140 of RNase-H*, the conjugates were proteolyzed very slowly. This resistance to degradation was not caused by inaccessibility of the ssrA tag or an inability of ClpXP to degrade proteins with side-chain linked ssrA tags. Our results support a model in which ClpX denatures proteins by initially unfolding structural elements attached to the degradation tag, suggest an important role for the position of the degradation tag and direction of force application, and correlate well with the mapping of local protein stability within RNase-H* by native-state hydrogen exchange.     

Synthesis,biological evaluation,and molecular docking investigation of benzhydrol- and indole-based dual PPAR-γ/FFAR1 agonists

Type-2 diabetes mellitus is a progressive cluster of metabolic disorders, representing a global public health burden affecting more than 366?million people worldwide. We recently reported the discovery of three series of novel agents showing balanced activity on two metabolic receptors, peroxisome proliferator activated receptor-γ (PPAR-γ) and free fatty acid receptor 1 (FFAR1), also known as GPCR40. Our designing strategy relied on linking the thiazolidinedione head with known GPCR privilege structures. To further investigate this concept, two new scaffolds, the benzhydrol- and indole-based chemotypes, were introduced here in. Our optimization campaign resulted in three compounds; 15a, 15c, and 15d, with affinities in the low micromolar range on both targets. In vivo study of selected test compounds, revealed that 15c possesses a significant anti-hyperglycemic and anti-hyperlipidemic activities superior to rosiglitazone in fat-fed animal models. Molecular docking analysis was conducted to explain the binding modes of both series. These compounds could lead to the development of the unique antidiabetic agent acting as insulin sensitizer as well as insulin secretagogue.     

Metagenomic‐based impact study of transgenic grapevine rootstock on its associated virome and soil bacteriome

For some crops, the only possible approach to gain a specific trait requires genome modification. The development of virus‐resistant transgenic plants based on the pathogen‐derived resistance strategy has been a success story for over three decades. However, potential risks associated with the technology, such as horizontal gene transfer (HGT) of any part of the transgene to an existing gene pool, have been raised. Here, we report no evidence of any undesirable impacts of genetically modified (GM) grapevine rootstock on its biotic environment. Using state of the art metagenomics, we analysed two compartments in depth, the targeted Grapevine fanleaf virus (GFLV) populations and nontargeted root‐associated microbiota. Our results reveal no statistically significant differences in the genetic diversity of bacteria that can be linked to the GM trait. In addition, no novel virus or bacteria recombinants of biosafety concern can be associated with transgenic grapevine rootstocks cultivated in commercial vineyard soil under greenhouse conditions for over 6 years.     

Assessment of gender-related differences in vitamin D levels and cardiovascular risk factors in Saudi patients with type 2 diabetes mellitus

Diabetes is a major risk factor for cardiovascular disease (CVD) including stroke, coronary heart disease, and peripheral artery disease. It remains a leading cause of mortality throughout the world, affecting both women and men. This investigation was aimed to study gender based differences in cardiovascular risk factors of adult population with type-2 diabetes mellitus (T2DM) and to check the correlation between serum HbA1C, lipid profile and serum vitamin D levels, in T2DM patients of Riyadh, Saudi Arabia. This hospital-based cross-sectional study involving subjects was divided into two gender based groups; normal male (800), diabetic male (800) and normal female (800) and T2DM females (800). Blood samples were analyzed for fasting glucose (FBG), HbA1c, total cholesterol (TC), triglycerides (Tg), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and serum levels of 25(OH)-vitamin D in all groups. All the glycemic control parameters and lipid profile parameters were found to be significantly different in diabetic vs non-diabetic group (p < 0.001) in both genders. The results also show that vitamin D concentration decreased significantly (p < 0.001) in diabetic patients than the healthy individuals in both the genders. Vitamin-D and HbA1C were negatively correlated in both males and females in T2DM patients and significant at P < 0.05. Our study reveals that dyslipidemia remains one of the major risk factors of CVD in T2DM. In addition to dyslipidemia, decreased levels of vitamin-D associated with increased HbA1C alarms the early diagnosis of Type 2 Diabetes.