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P Puigdoménech

Publications and source records attributed to P Puigdoménech.

15 recordsLinked to original sources
PubMed2005

A maize defective-kernel mutant (longcell) characterized by tubular cells, severe morphological alterations and induction of cell death.

Seeds of the longcell mutant in maize (Zea mays L) have a defective-kernel phenotype: the embryo aborts at the early coleoptilar stage and the endosperm is reduced in size. Mutant embryos have severe alterations in morphogenesis. They have a suspensor-, an embryo axis- and a scutellum-like structure, but the shoot apical meristem (SAM) is not formed. Scanning electron microscopy showed that most of the cells in longcell embryos are tubular and abnormally enlarged. The level of expression of several genes involved in basic metabolism is not severely affected during early and mid embryogenesis, but storage molecule accumulation is reduced. Genes which in normal conditions are only expressed after germination, are expressed during kernel development in the longcell seeds. Mutant embryos undergo cell death in late embryogenesis. Nuclei in dying embryos are TUNEL positive, and different genes coding for hydrolytic enzymes are up-regulated. The expression of genes related to oxidative stress is also altered in longcell embryos. These results lead us to suggest that the longcell mutant may be cytokinesis-defective.

Cell Death↗
PubMed2000

Benzyl derivatives of 2,1,3-benzo- and benzothieno[3,2-a]thiadiazine 2,2-dioxides: first phosphodiesterase 7 inhibitors.

The synthesis of a new family of benzyl derivatives of 2,1,3-benzo- and benzothieno[3,2-a]thiadiazine 2,2-dioxides was achieved. The biological data revealed the first heterocyclic family of compounds with PDE 7 inhibitory properties appearing to be a new objective for the treatment of T-cell-dependent disorders. The IC(50) values or percent inhibition values of the compounds against PDE 7 were calculated by testing them against human recombinant PDE 7 expressed in S. cerevisiae. In this expression system the only cyclic nucleotide hydrolyzing activity present in cell extracts corresponded to human PDE 7. Isoenzyme selectivity PDE 7 versus PDE 4 and PDE 3 was also measured. Considering simultaneously inhibition of the three different isoenzymes, monobenzyl derivatives 15 and 23 showed interesting PDE 7 potency (around 10 microM); although not statistically significant, a trend toward selectivity with respect to PDE 3 and PDE 4 was obtained. Benzothiadiazine 16, although less potent at PDE 7 (IC(50) = 25 microM), also showed a trend of selectivity toward PDE 3 and PDE 4. These compounds are considered the best leads for further optimization.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2000

Phosphodiesterase type 4 isozymes expression in human brain examined by in situ hybridization histochemistry and[3H]rolipram binding autoradiography. Comparison with monkey and rat brain.

We have examined the distribution of four different cyclic AMP-specific phosphodiesterase isozyme (PDE4A, PDE4B, PDE4C and PDE4D) mRNAs in the brain of different species by in situ hybridization histochemistry and by autoradiography with [3H]rolipram. We have compared the localization of each isozyme in human brain with that in rat and monkey brain. We have found that the four PDE4 isoforms display a differential expression pattern at both regional and cellular level in the three species. PDE4A, PDE4B and PDE4D are widely distributed in human brain, with the two latter appearing more abundant. In contrast, PDE4C in human brain, presents a more restricted distribution, limited to cortex, some thalamic nuclei and cerebellum. This is at variance with the distribution of PDE4C in rat brain, where it is found exclusively in olfactory bulb. In monkey brain, the highest expression for this isoform is found in the claustrum, and at lower levels in cortical areas and cerebellum. PDE4B presented a broad distribution, being expressed in both neuronal and non neuronal cell populations. In general, the distribution of binding sites visualized with [3H]rolipram correlated well with the expression of each PDE4 isozyme.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1998

Characterization of a gene encoding an abscisic acid-inducible type-2 lipid transfer protein from rice.

The cloning and sequence analysis of a novel gene that encodes a type 2 non-specific lipid transfer-like protein (LTP) from rice is reported. Sequence analysis revealed an ORF encoding a protein showing characteristics of the LTP proteins. However, rice LTP2 is more similar to heterologous LTPs than to rice LTP1, supporting the existence of two distinct families of plant LTPs. Ltp2 mRNA is accumulated only in mature seeds. In vegetative tissues, mRNA was only detected after treatment with abscisic acid (ABA), mannitol or NaCl. Transient expression experiments that the 61 nucleotides upstream of the TATA box, containing two ACGT boxes and the motif I, are sufficient for ABA responsiveness of the Ltp gene.

Abscisic Acid↗
PubMed1992

Expression of the gene encoding the PR-like protein PRms in germinating maize embryos.

The PRms protein is a pathogenesis-related (PR)-like protein whose mRNA accumulates during germination of maize seeds. Expression of the PRms gene is induced after infection of maize seeds with the fungus Fusarium moniliforme. To further our investigations on the expression of the PRms gene we examined the accumulation of PRms mRNA in different tissues of maize seedlings infected with F. moniliforme and studied the effect of fungal elicitors, the mycotoxin moniliformin, the hormone gibberellic acid, and specific chemical agents. Our results indicate that fungal infection, and treatment either with fungal elicitors or with moniliformin, a mycotoxin produced by F. moniliforme, increase the steady-state level of PRms mRNA. PRms mRNA accumulation is also stimulated by the application of the hormone gibberellic acid or by treatment with silver nitrate, whereas acetylsalicylic acid has no effect. In situ RNA hybridization in isolated germinating embryo sections demonstrates that the PRms gene is expressed in the scutellum, particularly in a group of inner cells, and in the epithelium lying at the interface of the scutellum and the endosperm. The pattern of expression of the PRms gene closely resembles that found for hydrolytic enzymes, being confined to the scutellum and the aleurone layer of the germinating maize seed. Our results suggest that the PRms protein has a function during the normal process of seed germination that has become adapted to serve among the defence mechanisms induced in response to pathogens during maize seed germination.

Blotting, Northern↗
PubMed1977

The interaction of histone H3 with histone H4 and with other histones studied by 19F nuclear magnetic resonance.

The behaviour, upon variations in ionic strength, pH and temperature of 19F nuclear nuclear magnetic resonance signals of the trifluoroacetonylated derivative of histone H3 is compared with those of the H3-H4 complex and of the Hv fraction (an equimolar mixture of H2A, H2B, H3 and h4). The line width of the 19F-labelled histone H3 signals increases with ionic strength or pH, an effect consistent with aggregation of the protein. In the case of H3-H4 complex or Hv the line width decreases at intermediate ionic strengths (0.1-0.25 M NaCl). This effect is interpreted as the consequence of the formation of a well defined structure with ionic strength. At high salt concentrations the line width increases as a consequence of the final rigid quaternary structure or of the formation of higher aggregates.

Animals↗
PubMed1976

Studies on the role and mode of operation of the very-lysine-rich histones in eukaryote chromatin. Nuclear-magnetic-resonance studies on nucleoprotein and histone phi 1-DNA complexes from marine invertebrate sperm.

Proton magnetic resonance and other measurements have been carried out in order to study the behaviour of the lysine-rich histones phi 1 in the sperm chromatin of certain marine invertebrates. Well defined particles (12 S) have been obtained from this chromatin by nuclease treatment. Chromatin solubility as a function of ionic strength shows a relaxation at salt concentrations higher than in the case of calf thymus nucleoprotein. Nuclear magnetic resonance (NMR) studies show that the release of histone from DNA occurs both in chromatin and in the reconstituted complexes at practically the same ionic strength as solubility relaxation. The higher the arginine content of a given phi 1, the higher the ionic strength at which both effects take place. The NMR results demonstrate that arginine residues are bound more strongly than lysine residues. The data overall show that phi 1 histones play a role in the contraction mechanism of sperm chromatin similar to that of H 1 histone in calf thymus chromatin. The highly contracted state of sperm chromatin is directly related to the increased arginine content of the phi 1 histone.

Animals↗
PubMed1975

Studies on the role and mode of operation of the very-lysine-rich histones in eukaryote chromatin. The conformation of phi1 histones from marine invertebrate sperm.

Proton magnetic resonance, circular dichroism and infrared spectroscopy are used to investigate the secondary and tertiary structure of three very lysine-rich histones from marine invertebrate sperm. At high ionic strength both Arbacia lixula and Holothuria tubulosa histone phi 1 are observed to contain 25-30% alpha-helix, no beta-structure and to form specific folded structures. Both phi 1 proton magnetic resonance spectra have perturbed methyl resonances at chemical shifts close to those observed for calf thymus H1, suggesting analogies in tertiary structure. Mytilus edulis histone phi 1 however, shows no spectroscopic evidence of secondary and tertiary structure on salt addition.

Amino Acids↗