TRIM32/USP11 Balances ARID1A Stability and the Oncogenic/Tumor-Suppressive Status of Squamous Cell Carcinoma

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MiR-204 regulates type 1 IP3R to control vascular smooth muscle cell contractility and blood pressure

MiR-204 is expressed in vascular smooth muscle cells (VSMC). However, its role in VSMC contraction is not known. We determined if miR-204 controls VSMC contractility and blood pressure through regulation of sarcoplasmic reticulum (SR) calcium (Ca²⁺) release. Systolic blood pressure (SBP) and vasoreactivity to VSMC contractile agonists (phenylephrine (PE), thromboxane analogue (U46619), endothelin-1 (ET-1), angiotensin-II (Ang II) and norepinephrine (NE) were compared in aortas and mesenteric resistance arteries (MRA) from miR-204^−/− mice and wildtype mice (WT). There was no difference in basal systolic blood pressure (SBP) between the two genotypes; however, hypertensive response to Ang II was significantly greater in miR-204^−/− mice compared to WT mice. Aortas and MRA of miR-204^−/− mice had heightened contractility to all VSMC agonists. In silico algorithms predicted the type 1 Inositol 1, 4, 5-trisphosphate receptor (IP₃R1) as a target of miR-204. Aortas and MRA of miR-204^−/− mice had higher expression of IP₃R1 compared to WT mice. Difference in agonist-induced vasoconstriction between miR-204^−/− and WT mice was abolished with pharmacologic inhibition of IP₃R1. Furthermore, Ang II-induced aortic IP₃R1 was greater in miR-204^−/− mice compared to WT mice. In addition, difference in aortic vasoconstriction to VSMC agonists between miR-204^−/− and WT mice persisted after Ang II infusion. Inhibition of miR-204 in VSMC in vitro increased IP₃R1, and boosted SR Ca²⁺ release in response to PE, while overexpression of miR-204 downregulated IP₃R1. Finally, a sequence-specific nucleotide blocker that targets the miR-204-IP₃R1 interaction rescued miR-204-induced downregulation of IP₃R1. We conclude that miR-204 controls VSMC contractility and blood pressure through IP₃R1-dependent regulation of SR calcium release.     

C-banding polymorphism and the analysis of nucleolar activity in Dasypyrum villosum (L.) Candargy,its added chromosomes to hexaploid wheat and the amphiploid Triticum dicoccum — D. villosum

Summary C-banding patterns and nucleolar activity were analyzed in Dasypyrum villosum, its added chromosomes to hexaploid wheat and the hexaploid amphiploid Triticum dicoccum-D. villosum. Two different populations of the allogamous species D. villosum (2n= 14, VV) from Greece and Italy were analyzed showing a similar polymorphism for C-banding pattern. Six of the seven addition lines were identified by their characteristic C-banding pattern. No polymorphism between both members of each added alien chromosome was found. Furthermore, nucleolar activity and competition were studied by using silver staining procedure. In D. villosum only one chromosome pair, A, was found to be responsible for organizing nucleoli. The results obtained in the amphiploid and in the addition lines demonstrate that nucleolar activity is restricted to SAT-chromosomes 1B and 6B of wheat, while those of D. villosum remain inactive.     

The stimulation of metallothionein synthesis in neuroblastoma IMR-32 by zinc and cadmium but not dexamethasone

Metallothioneins are a class of cysteine-rich and low molecular weight, metal-binding proteins that are inducible by a wide variety of agents, including metal ions, such as cadmium and zinc, glucocorticoid hormones, interferon, and tumor promoters. In an effort to delineate the regulation of the synthesis of the recently identified brain metallothionein-like protein, a study was undertaken to compare the induction of metallothionein in human neuroblastoma IMR-32 cells by zinc, cadmium, and dexamethasone using the human Chang liver cells as a control. Both cadmium (1 microM) and zinc (100 microM) significantly enhanced the incorporation of [35S]cysteine into metallothioneins isolated from both neuroblastoma and Chang liver cells. Dexamethasone in concentrations of 10 microM stimulated the synthesis of metallothionein in the Chang cells, whereas it had no effects on the synthesis of metallothionein in the neuroblastoma cells at concentrations ranging from 2.5--100 microM. The degree of stimulation of metallothionein synthesis in the Chang cells by cadmium and zinc was significantly higher than seen in neuroblastoma cells. The neuroblastoma IMR-32 exhibited less tolerance to the toxicity of both cadmium and zinc than the Chang cells, which may correlate with the inherent ability of these ions to induce metallothioneins in these dissimilar cells. The results of these studies are interpreted to indicate that the factors regulating the synthesis of metallothioneins in the Chang and neuroblastoma cells are not identical, suggesting also of the presence of dissimilar regulatory mechanisms in the liver and brain.     

Volatile production by Aspergillus versicolor as a possible cause of odor in houses affected by fungi

Aspergillus versicolor, which has been isolated from several mould affected houses was shown by laboratory studies under axenic conditions to produce several specific volatile compounds on water agar. These compounds were not produced by the fungus when grown on a rich malt extract medium or on several synthetic media. The volatile compounds were analysed by GC-MS. The majority of the peaks represented aromatic compounds. A non-aromatic substance which previously has been revealed by us among prominent volatile compounds sampled from building materials from so-called mould houses was produced only on water agar. According to a comparison with the mass spectrum and retention time of pure reference compound this compound is ethylhexanol, a compound not previously reported as a mould metabolite. The presence of this compound was correlated with pungent odor in the cultures.     

Degradation of the 32-kilodalton thylakoid-membrane polypeptide of Chlamydomonas reinhardi Y-1

Isolated thylakoid membranes of Chlamydomonas reinhardi Y-1 with the 32-kDa polypeptide either radioactively labelled or unlabelled were incubated in vitro under various conditions in order to gain information about the degradation of the 32-kDa polypeptide. The degradation was higher at pH 6 compared with pH 7 and pH 8 and exhibited a temperature maximum between 20° C and 25° C (pH 6, pH 8). A light-dependent part of the total degradation was linearly dependent on white light of energy fluence rate between 1 and 20 mW·cm^-2 at 25° C and leveled out at higher fluence rates. The degradation in light was only slightly stimulated by ATP but was reduced by 3-(3-4-dichlorophenyl)-1,1-dimethylurea. Adenosine-5-diphosphate and heparin (2.7 mM and 200 g per 100 l, respectively) known to inhibit kinases, caused a 50% decrease in degradation indicating that a phosphorylation step is involved in degradating the 32-kDa polypeptide. Out of various inhibitors specific for different types of proteases, only those for thiol- and endoproteases showed intense effects. These results point to a proteolytic degradation of the 32-kDa polypetide by a thylakoid-membrane-bound thiol-endoprotease. Its activity yields soluble breakdown products with relative molecular masses (M_rs) of 23, 16.5, 11.3 and 10.7 kDa, and these are accumulated in the in-vitro system. Partial proteolytic digestion of thylakoids with Staphylococcus aureus V8 protease results in at least two labelled breakdown products (M_rs 23, and 16.5 kDa). It is assumed that cleaving at identical amino-acid residues of the 32-kDa polypeptide by the thylakoid-membrane-bound thiolendoprotease and the V8 protease results in these two breakdown products. They are derived from subsequent cleavage at amino-acid residues 60–242 and 60–189 according to the deduced protein sequence (Erickson et al. 1984, EMBO J. 3, 2753–2762).Abbreviations DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) - LDS-PAGE lithiumdodecyl sulphate-polyacrylamide gel electrophoresis - M apparent molecular mass - PSII photosystem II - TCA trichloroacetic acid - Tris 2-amino-2-(hydroxymethyl)-1,3-propanediol     

Phosphorus nutrition of barley, buckwheat and rape seedlings. II. Influx and efflux of phosphorous by intact roots of different P status

Seedlings of barley (Hordeum vulgare L. cvs Salka and Zita), buckwheat (Fagopyrum esculentum Moench) and rape (Brassica napus L. ssp. napus cv. Line) were raised at 8 or 10 different extenral P concentrations in the range 0–2000 μM. Apart from P, the nutrient solutions were complete. Phosphate influx in roots of different P status was determined by use of a nutrient solution containing 0.1 mM³²P-labelled phosphate. A double labelling technique was used for simultaneous determination of influx (³³P) and efflux (³²P) of phosphorus by roots of barley and rape with three selected P levels. Flux determinations were also done in presence of a metabolic uncoupler (2,4-dinitrophenol) and a protein synthesis inhibitor (cycloheximide). Influx of phosphate was maximal at a certin optimal P level of the roots and decreased at both lower and higher P levels. Maximum phosphate influex [μmol (g root)-^?1 h^?1] were: rape 4,4, buckwheat 2.2, barley cv. Salka 1.6, barley cv. Zita 1.5. Both Hill plots and plots of the untransformed decreasing phosphate influx vs root P concentrations above the optimal were linear and had high correlation coefficients. The Hill coefficient varied between -3.1 and -4.2. The decrease of phosphate influx from the maximum to the lowest value at the highest P concentration of the root was 60–70%. Hence, phosphate influex appeared to be regulated through negative feedback by the internal level of phosphorous in the roots. The regulation mechanism seems bascially similar for the three species and may be of an allosteric type. P efflux from roots of low and optimal (with regard to P influx) P status was 15–20% of the simultaneous P influx. Contary to P influx, P efflux increased at high P status and almost eliminated (barley) or halved (rape) net P uptake. 2,4-Dinitrophenol reduced both P influx and P efflux by low P roots and gave linearly increasing P efflux with increasing root P status. This indicates that P efflux partly occurred by counter transport and ion exchange at the uptake sites, partly by passive P efflux along an electrochemical potential gradient. Phosphate influx was not affected by inhibition of barley root growth with cycloheximide, but P efflux increased considerably.     

Genetic relationship between o6 and pro-1 mutants in maize

Summary This paper reports that the opaque-6 (o6) mutation of maize, which causes seedling lethality and interferes in the endosperm with the synthesis of zeins and b-32 protein, is a proline requiring mutant functionally allelic to proline-1 (pro-1). Furthermore, immunological studies on the b-32 content of ten independently originated o6 and pro-1 alleles demonstrated that four alleles contain an apparently normal b-32 protein while the others are either devoid of it or contain trace amounts of cross-reacting proteins of lower molecular weight.     

Chronic Treatment of Rats with SCH-23390 or Raclopride Does Not Affect the Concentrations of DARPP-32 or Its mRNA in Dopamine-Innervated Brain Regions

DARPP-32 (dopamine- and cyclic AMP-regulated phosphoprotein, Mr = 32,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) is a neuronal phosphoprotein that is enriched in neurons which possess dopamine D1 receptors, particularly striatonigral neurons. In rat brain slices, the phosphorylation state of DARPP-32 is regulated by dopamine, acting through the dopamine D1 receptor and the adenylyl cyclase system. This study reports that chronic blockade (21 days) of either dopamine D1 receptors by SCH-23390 or dopamine D2 receptors by raclopride does not affect the concentrations of DARPP-32 in specific rat brain regions (striatum, thalamus, hippocampus, frontal cerebral cortical pole). Northern blot analysis indicates that the steady-state level of DARPP-32 mRNA in striatum is also unchanged by these treatments.