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M Boutry

Publications and source records attributed to M Boutry.

10 recordsLinked to original sources
PubMed1992

Differential expression within a three-gene subfamily encoding a plasma membrane H(+)-ATPase in Nicotiana plumbaginifolia.

Genomic and cDNA clones for the three members of a gene subfamily (pma) encoding a plasma membrane H(+)-translocating ATPase in Nicotiana plumbaginifolia were isolated and sequenced. They are between 95 and 96% identical at the deduced amino acid sequence level. Sequence comparisons with the corresponding tomato genes (Ewing, N.N., Wimmers, L.E., Meyer, D.J., Chetelat, R.T., and Bennett, A.B. (1990) Plant Physiol. 94, 1874-1881) indicate that divergence among the three N. plumbaginifolia pma genes occurred before the development of the Solanaceae family. Here, determination of pma1 transcription initiation sites reveals several 5' boundaries located 266 to 120 nucleotides upstream from the plasma membrane H(+)-ATPase translation initiation codon. The 5'-untranslated region contains a small open reading frame, 9 residues long. pma3 has a single, 264-nucleotide long 5' leader containing a 5-residue open reading frame. The latter is completely conserved in a corresponding tomato gene. These features suggest the possibility of translational regulation of plant pma genes. S1 nuclease protection assays on total cellular RNA isolated from different organs reveals that all three genes are expressed in leaf, stem, flower, and root tissues, albeit at different levels according to the organ and gene. The different genes for the plant H(+)-translocating ATPase are thus subject to differential regulation of transcription, possibly related to specific aspects of enzyme function.

Amino Acid Sequence↗
PubMed1992

Sequence and transcription analysis of mitochondrial plasmids isolated from cytoplasmic male-sterile lines of Vicia faba.

Three mitochondrial plasmids (1704, 1695 and 1478 bp) were isolated from sterile cytoplasms of Vicia faba L. and cloned into a bacterial plasmid vector. Their nucleotide sequence was found to be 99 to 100% homologous to their counterparts isolated from a fertile cytoplasm (J.A. Wahleithner and D.R. Wolstenholme, Curr Genet 12 (1987) 55-76). Several overlapping transcripts were localized in the region which is unique to each of the three plasmids. S1 nuclease mapping indicated for all of them several 3' termini but a unique 5' boundary which was located downstream of the consensus sequence CNTAAGTGANNNNNGAA also found at the transcript 5' boundary of other plant mitochondrial plasmids. Southern blot hybridization with nuclear DNA indicated the presence of nuclear sequences homologous to each plasmid.

Base Sequence↗
PubMed1978

Fatty acid, 3-beta-hydroxysterol, and ketone synthesis in the perfused rat liver. Effects of (--)-hydroxycitrate and oleate.

The effects of oleate and hydroxycitrate on the rate of long-chain fatty acid and 3-beta-hydroxysterol synthesis were measured in perfused rat livers. Metabolite measurements show that in livers from fed animals inhibition of fatty acid synthesis by oleate or hydroxycitrate is associated with an increase in the tissue content of glucose 6-phosphate and fructose 6-phosphate, and a diminution in glycolytic intermediates from fructose diphosphate to phosphoenolpyruvate. Oleate also causes an increase in the tissue content of long-chain fatty acyl-CoA and citrate. The increase in long-chain fatty acyl-CoA is larger in livers from starved as compared to fed rats, while the increase in citrate is larger in livers from fed as compared to starved rats. However, the increase in the citrate content of livers from fed rats occurs in a range where it causes no further activation of acetyl-CoA carboxylase in vitro. Ketogenesis by livers from fed rats perfused without free fatty acids is strongly inhibited by hydroxycitrate. However, ketogenesis is not inhibited by hydroxycitrate when livers from starved rats are perfused with oleate, and ketogenesis is increased somewhat by hydroxycitrate when livers from fed rats are perfused with oleate. These results are interpreted in terms of an extramitochondrial pathway of ketogenesis which operates in carbohydrate-fed animals. The intramitochondrial pathway predominates in starved animals, or when the concentration of fatty acids is high, or both. Other interpretations, which cannot be ruled out at present, are also considered.

Animals↗
PubMed1977

Energy-dependent uptake of calcium by the yeast Schizosaccharomyces pombe.

1. In resting cells of the fission yeast Schizosaccharomyces pombe, the uptake of calcium is stimulated by the addition of 90 mM glucose in the presence as in the absence of respiration and inhibited by Antimycin A in the absence of exogenous carbon source. This uptake therefore requires fermentative or respiratory metabolic energy. 2. The calcium uptake by S. pombe exhibits saturation kinetics and high affinity for calcium. At external pH 4.5, the apparent Km is 45 muM ca2+ 400 muM of other divalent cations exert competitive inhibitions of calcium uptake in the following order of affinities: Sr2+ greater than Mn2+ greater than Co2+ greater than Mg2+. Inhibition by KCl is also observed but is of non-competitive type and requires high concentrations of the order of 40 mM. 3. At 30 degrees C, the uptake rate of calcium is about 10-times higher at pH 8925 than at pH 4.0. An extrusion of 45Ca2+, the rate of which is estimated to be lower than one-fifth of the uptake, is observed in the presence of glucose when the external pH is acid. 4. At external pH 4.5, low concentrations of lanthanum chloride, ruthenium red and hexamine cobaltichloride are inhibitory for the uptake of calcium by the yeast cells. 5. In presence of Antimycin A, the uncouplers: NaN3, dinitrophenol, and concentrations of crobonylcyanide m-chlorophenylhydrazone higher than 80 muM inhibit the calcium uptake by glycolysing cells. In the presence of glucose, the K+ ionophore Dio-9 dnhances severalfold the uptake of calcium even at 2 degrees C. 6. It is concluded that S. pombe possess an active transport system for low concentrations of calcium. This transport seems to be dependent on an electric potential (negative inside) across the cellular membrane.

Antimycin A↗