Oncoprotein CIP2A promotes the disassembly of primary cilia and inhibits glycolytic metabolism

In most mammalian cells, the primary cilium is a microtubule‐enriched protrusion of the plasma membrane and acts as a key coordinator of signaling pathways during development and tissue homeostasis. The primary cilium is generated from the basal body, and cancerous inhibitor of protein phosphatase 2A (CIP2A), the overexpression of which stabilizes c‐MYC to support the malignant growth of tumor cells, is localized in the centrosome. Here, we show that CIP2A overexpression induces primary cilia disassembly through the activation of Aurora A kinase, and CIP2A depletion increases ciliated cells and cilia length in retinal pigment epithelium (RPE1) cells. CIP2A depletion also shifts metabolism toward the glycolytic pathway by altering the expression of metabolic genes related to glycolysis. However, glycolytic activation in CIP2A‐depleted cells does not depend on cilia assembly, even though enhanced cilia assembly alone activates glycolytic metabolism. Collectively, these data suggest that CIP2A promotes primary cilia disassembly and that CIP2A depletion induces metabolic reprogramming independent of primary cilia.     

Role of phage ϕ1 in two strains of <Emphasis Type="Italic">Salmonella</Emphasis> Rissen,sensitive and resistant to phage ϕ1

Background

The study describes the Salmonella Rissen phage ?1 isolated from the ?1-sensitive Salmonella Rissen strain R^W. The same phage was then used to select the resistant strain R^R?1+, which can harbour or not ?1.

Results

Following this approach, we found that ?1, upon excision from R^W cells with mitomycin, behaves as a temperate phage: lyses host cells and generates phage particles; instead, upon spontaneous excision from R^R?1+ cells, it does not generate phage particles; causes loss of phage resistance; switches the O-antigen from the smooth to the rough phenotype, and favors the transition of Salmonella Rissen from the planktonic to the biofilm growth.The R^W and R^R?1+ strains differ by 10 genes; of these, only two (phosphomannomutase_1 and phosphomannomutase_2; both involved in the mannose synthesis pathway) display significant differences at the expression levels. This result suggests that phage resistance is associated with these two genes.

Conclusions

Phage ?1 displays the unusual property of behaving as template as well as lytic phage. This feature was used by the phage to modulate several phases of Salmonella Rissen lifestyle.

     

Production of scopolamine by normal root culture of Hyoscyamus niger

Summary Normal root of Hyoscyamus niger was cultivated in various nutrient conditions to optimize root growth and scopolamine production. Nitrate or phosphate concentration had little effect on root growth, while the low levels of nitrate or phosphate enhanced specific scopolamine content by 44% and 39%, respectively. Glucose or fructose was not adequate for the root culture as a carbon source, while the root growth was markedly enhanced at high sucrose concentration (up to 9%). The growth rate (0.59g dw./L.d.) and scopolamine productivity (1.98 mg/L.d.) was increased greater in roots with 9% initial sucrose concentration as compared to 3% sucrose (0.28 g dw./L.d., 0.98 mg/L.d.)     

Cross-linking of wheat starch and hydroxypropylated wheat starch in alkaline slurry with sodium trimetaphosphate

Wheat starch was cross-linked at 40 °C and pH 11.0 by slurrying the starch (30% solids) in a solution of sodium trimetaphosphate (STMP), sodium hydroxide, and sodium sulfate. The extent of cross-linking was determined by an increase in alkaline fluidity or by a decrease in alkaline clarity. Response surface analysis showed that cross-linking increased with increasing levels of STMP (0.5-1.5%, based on starch, bos) and sodium sulfate (0–4.0%, bos) over a reaction period of 120–720 min. A regression equation with first and second order terms showed that STMP and sodium sulfate concentrations and the reaction time accounted for 99% of the variability in alkaline fluidity. Wheat starch (37% slurry) was hydroxypropylated by reaction with propylene oxide (8%, bos) for 24h at 45 °C in alkali (pH 11.5) containing 16.0% sodium sulfate (bos). The hydroxypropylated (4.5wt%) wheat starch (DS 0.12-0.13) was not isolated but was cross-linked with STMP (0.1-0.5%, bos) over a 10–40 min reaction period. A comparison of pasting curves at pH 3.5 showed that some of the cross-links produced by STMP were less stable than those produced by phosphoryl chloride, indicating a low level of pyrophosphate as well as monophosphate cross-links. The less stable cross-links were diminished by changing reaction conditions with STMP.     

Enhancement of growth of tilapia Oreochromis niloticus in iso-osmotic medium

Tilapia ( Oreochromis niloticus ) kept in 15 ppt sea water (roughly iso-osmotic salinity) had higher growth rates than fish kept in 0 ppt (freshwater) or 30 ppt seawater, but circulating level of growth hormone was highest in fish exhibiting the poorest growth rate (30 ppt seawater). Serum thyroxine concentration was highest in 15 ppt seawater. Intestinal trypsin may play a role in promoting growth in iso-osmotic salinity since its activity was highest in fish cultured in 15 ppt seawater. The results indicate that changes in the digestive power, coupled with changes in thyroxine secretion, may account for the variations in growth rate in tilapia reared under different salinities.     

Preferential Use of Acetate over Glucose Involves Acetate-Mediated Inhibition of Glucose Uptake during Diauxic Growth of Carrot Cells

It has been reported that suspension-cultured rice cells grownon mixed carbon sources of glucose (Glc) and acetate exhibiteddiauxic growth in which acetate was the preferred carbon source(Lee and Lee 1996). Carrot (Daucus carota L.) suspension cells,showing a diauxic growth very similar to that of rice cells,were used to delineate the mechanisms underlying this preferentialuse of acetate over Glc. Uptakes of both Glc and 3-O-methylglucose(3-OMG), a non-metabolizable Glc analogue, were similarly inhibitedwhen acetate or butylate, weak acids which are capable of transportingprotons into the cytosol, were present in the uptake assay mixturecontaining cells harvested during the Glc-utilizing second growthphase. Inhibition of Glc uptake by these weak acids was similarwhen equivalent experiments were carried out with isolated plasmamembranes. It was further shown that Glc uptake, which requiresa proper proton gradient across the plasma membranes, was inhibitedduring the first growth phase by acetate-mediated alkalizationof growth medium and/or simultaneous acidification of cytosol.This study strongly suggests that Glc utilization in plant cellsis inhibited by co-presenting carbon source(s) which can alterthe proton gradient across the plasma membrane. (Received April 1, 1999; Accepted July 23, 1999)     

Three-Dimensional Reconstruction of Hematopoietic Organ of Bombyx mori Larva

Three‐dimensional reconstructions of a hematopoietic organ (HPO) from Bombyx mori larva were undertaken using light and electron microscopy. Each compact islet varied in sizes, but in the central area of the HPO their size became smaller. Compact islets and loose islets were made up of prohemocytes, plasmatocytes, and reticular cells, but there were differences in the proportions of these cells. Within the cytoplasm of reticular cells and within their cell projection, vacuoles were observed. Cell proliferation occurs primarily in the compact islets, and differentiation associated with the reticular cells occurs primarily in the loose islets. It can be inferred that reticular cells have a significant influence on proliferation and differentiation associated with hematopoiesis. According to the results of the 3‐D reconstruction, one reticular cell is in contact with eight or nine hemocytes. Each reticular cell is presumably of approximately ten hemocytes. Movies relevant to Figs. 3, 4 and 5 can be found at http://biotech.korea.ac.kr/ cellbio/pages/ 3D‐results.html.     

Structure-antiviral activity relationships of cecropin A-magainin 2 hybrid peptide and its analogues.

In order to elucidate the structure-antiviral activity relationship of cecropin A (1-8)-magainin 2 (1-12) (termed CA-MA) hybrid peptide, several analogues with amino acid substitutions were synthesized. In a previous study, it was shown that serine at position 16 in CA-MA hybrid peptide was very important for antimicrobial activity. Analogues were designed to increase the hydrophobic property by substituting a hydrophobic amino acid residue (S --> A, V, F or W, position 16) in the CA-MA hybrid peptide. In this study, the structure-antiviral activity relationships of CA-MA and its analogues were investigated. In particular, substitution of Ser with a hydrophobic amino acid, Val, Phe or Trp at position 16 caused a dramatic increase in the virus-cell fusion inhibitory activity. These results suggested that the hydrophobicity at position 16 in the hydrophobic region of CA-MA is important for potent antiviral activity.     

Optimization of operating variables for polyphenol extraction from lipid-extracted microalgae using acid-catalyzed hot-water extraction

Microalgae are a promising source of lipids for biodiesel production, which has the potential to replace fossil fuels without affecting the supply of foods and crop products. From the production of biodiesel, a solid waste known as lipid-extracted microalgae (LEM) is generated as a byproduct, and it is considered a rich source of antioxidant compounds, mainly polyphenols. In this study, optimization of the process variables of acid-catalyzed hot-water extraction was performed at low temperature in order to increase the production of polyphenols from LEM (Tetraselmis KCTC 12236BP). A statistically based method was used to optimize key variables, including extraction temperature, time, and sulfuric acid concentration. The results indicated that all process variables had significant effects on the extraction of polyphenols (p < 0.05). For instance, polyphenol levels increased in accordance with the increase of the three variables. The most economical optimal conditions were 100°C, 46.8 min, and 0.32 N H₂SO₄, under which polyphenol yield was 8.04 mg gallic acid equivalent (GAE)/g dry matter (DM), 5.2-fold higher than that from hot-water extraction without optimization.