Copper retention by a strain ofBacillus

Summary A survey has been made of the copper accumulation by resting cells of bacteria selected as copper-resistant, isolated from activated sludges. The best selected strain, classified asBacillus, retained copper at up to 3.8% of its cell dry weight. These values were lower in the presence of glucose, unlike a type culture ofBacillus cereus, in which the retention of copper was higher when glucose was present. Possible reasons for these changes in uptake of both strains are suggested.     

Glycosphingolipid expression in spontaneously aborted fetuses and placenta from blood group p women. Evidence for placenta being the primary target for anti-Tja-antibodies

A 12-week-old fetus and one 17-week-old fetus + placenta were obtained after spontaneous abortions from two women of blood group p. The 17-week-old fetus was dissected into intestine, liver, brain and residual tissue. Nonacid glycosphingolipid fractions were prepared from the tissues. Glycolipid characterization was carried out using thin layer chromatography immunostained with monoclonal antibodies and bacteria and by¹H NMR spectroscopy and mass spectrometry. In the placental fraction substantial amounts of globotetraosylceramide (P-antigen) and globotriaosylceramide (P^k-antigen) were identified. In contrast, the fetuses contained only trace amounts of these structures, as revealed by immunostaining. These results indicate that the primary target for the antibodies of the anti-Tj^a serum is the placenta tissue, resulting in termination of the pregnancy.     

Structure and expression of a gene from Arabidopsis thaliana encoding a protein related to SNF1 protein kinase

The AKin10 gene from Arabidopsis thaliana encoding a putative Ser/Thr protein kinase (PK) has been isolated and characterized. The AKin10-encoding gene is located on a genomic 5.4-kb BamHI fragment and contains ten introns, one being located in the 5' untranslated region. The deduced amino acid sequence of AKin10 is 65% identical over the catalytic domain to the yeast PK (SNF1). SNF1 is essential for the derepression of many glucose-repressible genes, including Suc2 which encodes invertase. Southern blot hybridization experiments suggested the presence of one copy of the gene per haploid genome of A. thaliana. Northern hybridization experiments indicated that this gene is expressed in roots, shoots and leaves. AKin10 may play an important role in a signal transduction cascade regulating gene expression and carbohydrate metabolism in higher plants.     

Effect of alpha-adrenoreceptors in the control of spontaneous motility and morphine withdrawal syndrome.

The effects of different alpha-2 agonists on the spontaneous motility in naive and morphine tolerant mice were studied. Clonidine caused a reduction at the lower (1-3 micrograms Kg-1 i.p.) and higher (100 micrograms Kg-1 i.p.) doses and no effect at 10-30 micrograms Kg-1 i.p. in naive mice, while an increase was found at the intermediate doses (10-30 micrograms Kg-1 i.p.) in morphine tolerant mice. The clonidine-induced inhibition on spontaneous motility at the lower and higher doses was prevented both in naive and tolerant mice by idazoxan pretreatment. In morphine-treated animals the increase induced by clonidine was antagonized by prazosin. The action of guanabenz and guanfacine on locomotion differed from clonidine, by producing inhibition only at higher doses (100-300 micrograms Kg-1 i.p.). Clonidine, but not guanfacine or guanabenz, prevented the withdrawal syndrome precipitated by naloxone. Thus the only alpha-2 agonistic properties do not appear sufficient to explain the prevention of morphine abstinence by clonidine in mice, which can represent a single model to screen anti-withdrawal drugs.     

Acid phosphatase-11, a tightly linked molecular marker for root-knot nematode resistance in tomato: from protein to gene,using PCR and degenerate primers containing deoxyinosine

With a view to cloning the root-knot nematode resistance gene Mi in tomato by chromosome walking, we have developed a molecular probe for the tightly linked acid phosphatase-1 (Aps-1) locus. The acid phosphatase-1 allozyme (APS-1¹), encoded by the Aps-1 ¹ allele originating from Lycopersicon peruvianum, was purified to apparent homogeneity from tomato roots and suspension cells. Microsequencing of CNBr and tryptic peptides generated from APS-1¹ provided a partial amino acid sequence, which accounted for approximately 23% of the protein and revealed two stretches of homology with soybean proteins KSH3 and VSP27, comprising 22 matches within 26 amino acid residues. The partial amino acid sequence information enabled us to isolate a 2.4 kb genomic Aps-1 ¹ sequence by means of the polymerase chain reaction (PCR), primed by degenerate pools of oligodeoxyribonucleotides, synthesized on the basis of the amino acid sequences. Synthesis of the 2.4 kb PCR product was specific for genomic templates carrying the L. peruvianum Aps-1 ¹ allele. Crucial to the priming specificity and the synthesis of the 2.4 kb genomic sequence was the use of degenerate primer pools in which the number of different primer species was limited by incorporating deoxyinosine phosphate residues at three and four base ambiguities. In using cDNA as a template, a 490 bp sequence was obtained, indicating a high proportion of intron sequences in the 2.4 kb genomic Aps-1 ¹ sequence. The Aps-1 ¹ origin of the PCR product was confirmed by RFLP (restriction fragment length polymorphism) analysis, using both a chromosome 6 substitution line and a pair of nearly isogenic lines, differing for a small chromosomal region around the Aps-1/Mi loci.     

Mouse Chromosome 7

Chair of Committee for Mouse Chromosome 7     

Androgen receptor heterogeneity in LNCaP cells is caused by a hormone independent phosphorylation step

Androgen receptor synthesis and modification were studied in the human LNCaP cell line. Immunoblotting showed that the androgen receptor migrated as a closely spaced 110–112 kDa doublet on SDS-PAGE gels. Most of the receptor protein is present in the higher molecular mass form. Labelling experiments with [³⁵S]methionine showed that the androgen receptor is synthesized as a single 110 kDa protein which is rapidly converted to a 112 kDa protein. Upon alkaline phosphatase treatment a gradual elimination of the 112 kDa isoform with a concomitant increase of the 110 kDa isoform was seen, indicating that the observed 110 to 112 kDa upshift reflects androgen receptor phosphorylation. Furthermore, it is shown that both isoforms can bind hormone and undergo a hormone dependent transformation to a tight nuclear binding form, indicating that the 110 to 112 kDa conversion is not an obligatory step for hormone binding or receptor transformation.     

In-situ localization of chalcone synthase mRNA in pea root nodule development

In this paper studies on the role of flavonoids in pea root nodule development are reported. Flavonoid synthesis was followed by localizing chalcone synthase (CHS) mRNA in infected pea roots and in root nodules. In a nodule primordium, CHS mRNA is present in all cells of the primordium. Therefore it is hypothesized that the Rhizobium Nod factor induces cell division in the root cortex by stimulating the production of flavonoids that function as auxin transport inhibitors. In nodules CHS mRNA is predominantly present in a region at the apex of the nodule consisting of meristematic and cortical cells. These cells are not infected by Rhizobium. Therefore it is postulated that CHS plays a role in nodule development rather than in a defence response. In roots CHS mRNA is located at a similar position as in nodules, suggesting that CHS has the same function in both root and nodule development. When nodules are formed by mutants of Rhizobium leguminosarum bv. viciae that are unable to secrete β(1-2) glucan and to synthesize the O-antigen containing LPS I, CHS genes are also expressed in regions of the nodule that are infected by Rhizobium. It is postulated that the impaired development of nodules formed by these mutants is due to an induction of a plant defence response.     

Different oligosaccharides accumulate in the brain and urine of a cat with α-mannosidosis: structure determination of five brain-derived and seventeen urinary oligosaccharides

Five brain-derived and 17 urinary oligomannose-type oligosaccharides were isolated by ion-exchange chromatography on Mono Q or Dowex, followed by HPLC on Lichrosorb-NH₂ from a Persian cat suffering from -mannosidosis. The structures ofthe carbohydrate chains were determined by 500- or 600-MHz¹H-NMR spectroscopy. Different oligosaccharide patterns were found in brain and urine. 99% of the urinary oligosaccharides possess an (1-6)-linked mannose residue attached to -mannose, whereas only 5% of the brain-derived oligosaccharides contain such a residue. Furthermore, of the urinary carbohydrate chains 71% end with Man1-4GlcNAc1-4GlcNAc and 29% end with Man1-4GlcNAc, whereas the corresponding amounts are 23% and 77%, respectively, for the brain-derived oligosaccharides.Abbreviations MLEV-17 composite pulse devised by M. Levitt - HOHAHA homonuclear Hartman-Hahn spectroscopy - TPPI time-proportional phase incrementation - 2D two dimensional - GlcNAc N-acetylglucosamine - Man mannose - Fuc fucose     

Modulation of the beta-adrenergic response in cultured rat heart cells

Incubation of rocker-cultured neonatal rat heart cells with 3 mM L(+)-lactate led to a sharp increase in the sensitivity of cardiomyocytes to the beta-adrenergic agonist isoprenaline, as measured by their chronotropic response. This effect was accompanied by a reduction in the arachidonic acid content of the total phospholipids. The phospholipase A₂-activator melittin as well as free arachidonic acid induced this supersensitivity to the same degree. On the other hand, the L(+)-lactate-evoked supersensitivity could be blocked by the phospholipase A₂ inhibitors mepacrine and n-bromophenacyl-bromide, suggesting an involvement of phospholipase A₂ in the process of beta-adrenergic sensitization. The sensitizing action of arachidonic acid was blocked by the lipoxygenase inhibitors esculetin and nordihydroguaiaretic acid, but not by the cyclooxygenase inhibitor indomethacin. Supersensitivity was likewise evoked by 15-S-hydroxyeicosatetraenoic acid (15-S-HETE), but not by 5-S-HPETE or 5-S-HETE. These findings suggest that the phospholipase A₂-15-lipoxygenase pathway plays a role in the induction of beta-adrenergic supersensitivity in the cultured cardiomyocytes and point to a new physiological role of the lipoxygenase product 15-S-HETE.Abbreviations NDGA nordihydroguaiaretic acid - HETE hydroeicosatetraenoic acid - HPETE hydroperoxyeicosatetraenoic acid