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31.
Marie-Jo Soncini 《Review of Palaeobotany and Palynology》1992,70(4):325-338
Moroccan phosphate deposits from the Phosphate Plateau (Oulad Abdoun basin, near Khouribga) contain varied and well preserved dinoflagellate cysts. Among them, a new genus: Bitubericysta and three new species: B. boroujiana, Liesbergia abdounensis and Spinidinium stellatum are described in this paper. The two gonyaulacoid cysts have been found in Upper Paleocene (Thanetian) and Lower Eocene (Ypresian) sediments, the peridinioid cyst has been observed in Upper Paleocene (Thanetian) and basal Eocene (basal Ypresian) material. 相似文献
32.
Jocelyne Caboche Nadia Mitrovic Françoise Le Saux † Marie-Jo Besson ré Sauter‡ Yves Maurin 《Journal of neurochemistry》1989,52(2):419-427
Binding assays of [3H]muscimol and [3H]-flunitrazepam have been performed on brain homogenates of brainstem, cerebellum, and forebrain of genetically epileptic quaking (qk) mutant mice 20, 40, 70, and 90 days old and their corresponding controls of the same strain (C57BL/6J). The endogenous gamma-aminobutyric acid (GABA) content has been determined in various brain regions of 70-day-old qk and control mice. Finally, the behavioral effects of diazepam, of the mixed GABAA/GABAB receptor agonist progabide, and of the selective GABAB receptor agonist baclofen have been assessed in adult qk mutants. Our results strongly suggest a lack of involvement of GABAergic neurotransmission in the inherited epilepsy of the qk mutant mouse. 相似文献
33.
Sucrose synthesis and sucrose hydrolysis in cut carnations (Dianthus caryophyllus) supplied with glucose solution .
Sucrose synthesis and hydrolysis in cut carnations supplied with a glucose solution have been investigated using both entire floral branches and floral branches without any of their organs (petals, non-petaloid pieces, leaves) and isolated organs. – The flower is a more active sink that the leaves. The transformationn of glucose into sucrose is essential for the ability of the flower to use the exogenous glucose. All organs of the floral branch (petals, ovaries and sepals, leaves, stem) are able to form sucrose. The hydrolysis of the obtained sucrose occurs nearly exclusively in the petals. 相似文献
Sucrose synthesis and hydrolysis in cut carnations supplied with a glucose solution have been investigated using both entire floral branches and floral branches without any of their organs (petals, non-petaloid pieces, leaves) and isolated organs. – The flower is a more active sink that the leaves. The transformationn of glucose into sucrose is essential for the ability of the flower to use the exogenous glucose. All organs of the floral branch (petals, ovaries and sepals, leaves, stem) are able to form sucrose. The hydrolysis of the obtained sucrose occurs nearly exclusively in the petals. 相似文献
34.
Marie-Jo Halaby Benjamin R. E. Harris W. Keith Miskimins Margot P. Cleary Da-Qing Yang 《Molecular and cellular biology》2015,35(23):4006-4017
Synthesis of the p53 tumor suppressor and its subsequent activation following DNA damage are critical for its protection against tumorigenesis. We previously discovered an internal ribosome entry site (IRES) at the 5′ untranslated region of the p53 mRNA. However, the connection between IRES-mediated p53 translation and p53''s tumor suppressive function is unknown. In this study, we identified two p53 IRES trans-acting factors, translational control protein 80 (TCP80), and RNA helicase A (RHA), which positively regulate p53 IRES activity. Overexpression of TCP80 and RHA also leads to increased expression and synthesis of p53. Furthermore, we discovered two breast cancer cell lines that retain wild-type p53 but exhibit defective p53 induction and synthesis following DNA damage. The levels of TCP80 and RHA are extremely low in both cell lines, and expression of both proteins is required to significantly increase the p53 IRES activity in these cells. Moreover, we found cancer cells transfected with a shRNA against TCP80 not only exhibit decreased expression of TCP80 and RHA but also display defective p53 induction and diminished ability to induce senescence following DNA damage. Therefore, our findings reveal a novel mechanism of p53 inactivation that links deregulation of IRES-mediated p53 translation with tumorigenesis. 相似文献
35.
The immunoglobulin superfamily (IgSF) is a heterogenic group of proteins built on a common fold, called the Ig fold, which
is a sandwich of two β sheets. Although members of the IgSF share a similar Ig fold, they differ in their tissue distribution,
amino acid composition, and biological role.
In this paper we report an up-to-date compilation of the IgSF where all known members of the IgSF are classified on the basis
of their common functional role (immune system, antibiotic proteins, enzymes, cytokine receptors, etc.) and their distribution
in tissue (neural system, extracellular matrix, tumor marker, muscular proteins, etc.), or in species (vertebrates, invertebrates,
bacteria, viruses, fungi, and plants). The members of the family can contain one or many Ig domains, comprising two basic
types: the constant domain (C), with seven strands, and the variable domain (V), with eight, nine, or ten strands. The different
overviews of the IgSF led to the definition of new domain subtypes, mainly concerning the C type, based on the distribution
of strands within the two sheets.
The wide occurrence of the Ig fold and the much less conserved sequences could have developed from a common ancestral gene
and/or from a convergent evolutionary process. Cell adhesion and pattern recognition seem to be the common feature running
through the entire family.
Received: 4 June 1997 / Accepted: 15 September 1997 相似文献
36.
37.
Three of the protein kinases activated by hypoosmotic stress in Arabidopsis thaliana cell suspensions were previously characterized [FEBS, 2002, 527, 43-50] as mitogen-activated protein (MAP) kinases and two of them corresponded to Arabidopsis mitogen-activated protein kinase 6 (MPK6) (44 kDa) and MPK3 (39 kDa). The third MAP kinase was identified here to MPK4, using a corresponding specific antibody. Like MPK6 and MPK3, MPK4 activity is clearly inhibited by apigenin and MPK4 activation by hypoosmolarity needs upstream phosphorylation events. Activation of the 3 MAP kinases, MPK3, 4 and 6, was confirmed in plantlets submitted to hypoosmotic stress. The action of a biotic signal, flagellin, was also demonstrated to induce the activations of the 3 MAP kinases. Using the mutant displaying MPK4 gene inactivation, the independence of the MPK3 and MPK6 activations towards the presence of MPK4 was demonstrated, both in hypoosmotic and flagellin signalling pathways. Although MPK4 was not activated by hyperosmolarity in cell suspensions nor in seedlings, a possible negative regulation of hyperosmolarity resistance by MPK4 is suggested, based both on phenotype and downstream gene expression studies. 相似文献
38.
α-
Jean-Paul Mornon Dyna Halaby Marc Malfois Patrick Durand Isabelle Callebaut Annette Tardieu 《International journal of biological macromolecules》1998,22(3-4)
New results obtained from a two-dimensional sequence analysis of the small heat shock protein (shsp) family are described. It is confirmed that the conserved C-terminal α-crystallin domain is essentially made of β-strands, most probably two groups of β-strands separated by a large loop. A direct correspondence between the putative β-strands that have been identified in shsps and the seven β-strands of a classical immunoglobulin-like fold is proposed. The hypothesis that the shsp family could belong to the immunoglobulin superfamily (IgSF) is consistent with the ubiquitous distribution and the multifunctional properties of the crystallins that are now emerging. 相似文献
39.
Diana J Persat F Staquet MJ Assossou O Ferrandiz J Gariazzo MJ Peyron F Picot S Schmitt D Vincent C 《FEMS immunology and medical microbiology》2004,42(3):321-331
Migration and maturation of human dendritic cells derived from CD34+ progenitor cells (DC) infected by Toxoplasma gondii were studied in an in vitro model. We demonstrated that infection with virulent type I strains RH and ENT or type II low virulent strains PRU and CAL induced DC migration towards MIP-3beta. However, type II strains induced a higher percentage of migrating cells than that induced by type I strains or positive controls (chemical allergen or lipopolysaccharides). Type II strains produced soluble factors responsible of the high migration whereas heat killed tachyzoites did not induced a migration higher than positive controls. We also demonstrated that infection by virulent strains and not by type II stains or heat killed tachyzoites triggers DC maturation. A soluble factor released by type II strains was responsible of the absence of DC maturation. Taken together, these results demonstrated that the interference of T. gondii in the behaviour of DC functions is related to the strain types and can be supported by secretion of soluble factors by the parasite. 相似文献
40.
Duhoux FP Ameye G Lambot V Herens C Lambert F Raynaud S Wlodarska I Michaux L Roche-Lestienne C Labis E Taviaux S Chapiro E Nguyen-Khac F Khac FN Struski S Dobbelstein S Dastugue N Lippert E Speleman F Van Roy N De Weer A Rack K Talmant P Richebourg S Mugneret F Tigaud I Mozziconacci MJ Laibe S Nadal N Terré C Libouton JM Decottignies A Vikkula M Poirel HA;Groupe Francophone de Cytogénétique Hématologique 《PloS one》2011,6(10):e26311
Fluorescence in situ hybridization was performed to characterize 81 cases of myeloid and lymphoid malignancies with cytogenetic 1p36 alterations not affecting the PRDM16 locus. In total, three subgroups were identified: balanced translocations (N = 27) and telomeric rearrangements (N = 15), both mainly observed in myeloid disorders; and unbalanced non-telomeric rearrangements (N = 39), mainly observed in lymphoid proliferations and frequently associated with a highly complex karyotype. The 1p36 rearrangement was isolated in 12 cases, mainly myeloid disorders. The breakpoints on 1p36 were more widely distributed than previously reported, but with identifiable rare breakpoint cluster regions, such as the TP73 locus. We also found novel partner loci on 1p36 for the known multi-partner genes HMGA2 and RUNX1. We precised the common terminal 1p36 deletion, which has been suggested to have an adverse prognosis, in B-cell lymphomas [follicular lymphomas and diffuse large B-cell lymphomas with t(14;18)(q32;q21) as well as follicular lymphomas without t(14;18)]. Intrachromosomal telomeric repetitive sequences were detected in at least half the cases of telomeric rearrangements. It is unclear how the latter rearrangements occurred and whether they represent oncogenic events or result from chromosomal instability during oncogenesis. 相似文献