47 research outputs found

    Effect of isolated AMP deaminase deficiency on skeletal muscle function

    Get PDF
    Jidong Cheng, Hiroko Morisaki, Naomi Sugimoto, Atsushi Dohi, Takuya Shintani, Erika Kimura, Keiko Toyama, Masahito Ikawa, Masaru Okabe, Itsuro Higuchi, Satoshi Matsuo, Yasuaki Kawai, Ichiro Hisatome, Takako Sugama, Edward W. Holmes, Takayuki Morisaki, Effect of isolated AMP deaminase deficiency on skeletal muscle function, Molecular Genetics and Metabolism Reports, Volume 1, 2014, Pages 51-59, ISSN 2214-4269, https://doi.org/10.1016/j.ymgmr.2013.12.004

    Regulation of RKIP Function by Helicobacter pylori in Gastric Cancer

    Get PDF
    Helicobacter pylori (H. pylori) is a gram-negative, spiral-shaped bacterium that infects more than half of the world’s population and is a major cause of gastric adenocarcinoma. The mechanisms that link H. pylori infection to gastric carcinogenesis are not well understood. In the present study, we report that the Raf-kinase inhibitor protein (RKIP) has a role in the induction of apoptosis by H. pylori in gastric epithelial cells. Western blot and luciferase transcription reporter assays demonstrate that the pathogenicity island of H. pylori rapidly phosphorylates RKIP, which then localizes to the nucleus where it activates its own transcription and induces apoptosis. Forced overexpression of RKIP enhances apoptosis in H. pylori-infected cells, whereas RKIP RNA inhibition suppresses the induction of apoptosis by H. pylori infection. While inducing the phosphorylation of RKIP, H. pylori simultaneously targets non-phosphorylated RKIP for proteasome-mediated degradation. The increase in RKIP transcription and phosphorylation is abrogated by mutating RKIP serine 153 to valine, demonstrating that regulation of RKIP activity by H. pylori is dependent upon RKIP’s S153 residue. In addition, H. pylori infection increases the expression of Snail, a transcriptional repressor of RKIP. Our results suggest that H. pylori utilizes a tumor suppressor protein, RKIP, to promote apoptosis in gastric cancer cells

    Origins of the Tumor Microenvironment: Quantitative Assessment of Adipose-Derived and Bone Marrow–Derived Stroma

    Get PDF
    To meet the requirements for rapid tumor growth, a complex array of non-neoplastic cells are recruited to the tumor microenvironment. These cells facilitate tumor development by providing matrices, cytokines, growth factors, as well as vascular networks for nutrient and waste exchange, however their precise origins remain unclear. Through multicolored tissue transplant procedures; we have quantitatively determined the contribution of bone marrow-derived and adipose-derived cells to stromal populations within syngeneic ovarian and breast murine tumors. Our results indicate that subpopulations of tumor-associated fibroblasts (TAFs) are recruited from two distinct sources. The majority of fibroblast specific protein (FSP) positive and fibroblast activation protein (FAP) positive TAFs originate from mesenchymal stem/stromal cells (MSC) located in bone marrow sources, whereas most vascular and fibrovascular stroma (pericytes, α-SMA+ myofibroblasts, and endothelial cells) originates from neighboring adipose tissue. These results highlight the capacity for tumors to utilize multiple sources of structural cells in a systematic and discriminative manner

    Cotranslational protein assembly imposes evolutionary constraints on homomeric proteins

    Get PDF
    Cotranslational protein folding can facilitate rapid formation of functional structures. However, it might also cause premature assembly of protein complexes, if two interacting nascent chains are in close proximity. By analyzing known protein structures, we show that homomeric protein contacts are enriched towards the C-termini of polypeptide chains across diverse proteomes. We hypothesize that this is the result of evolutionary constraints for folding to occur prior to assembly. Using high-throughput imaging of protein homomers in vivo in E. coli and engineered protein constructs with N- and C-terminal oligomerization domains, we show that, indeed, proteins with C-terminal homomeric interface residues consistently assemble more efficiently than those with N-terminal interface residues. Using in vivo, in vitro and in silico experiments, we identify features that govern successful assembly of homomers, which have implications for protein design and expression optimization

    Ring Expansion of Cyclobutylmethylcarbenium Ions to Cyclopentane or Cyclopentene Derivatives and Metal-Promoted Analogous Rearrangements

    Full text link

    ACTRAN numerical study on the effects of intake geometry and length on fan tone noise propagation and radiation

    No full text
    In this study, the geometry of a drooped intake of a scale rig for typical turbofan engines is artificially modified to create fictitious shorter intake geometries in order to investigate the impact of the intake length on the forward radiated fan noise. The study has been conducted by using three-dimensional ACTRAN TM models, and computations were performed over a wide range of frequencies. The noise source of interest is buzz-saw tones, hence rotor-locked single mode at the fan plane at integer-multiples of the engine shaft rotation speed at each engine order was used to define the noise source. In parallel, ACTRAN TM predictions by using the axisymmetric models generated based on the sideline profile of the drooped intake have also been performed for comparison and understanding the three-dimensional effect on the radiation directivities. The ACTRAN results show that the impact of the intake length is quite small if the intake is not acoustically lined. In case of lined intake, however, the far-field directivity can be significantly modified by the change of the intake length. <br/
    corecore