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191.
Molinari J. F.; Moore W. R.; Clark J.; Tanaka R.; Butterfield J. H.; Abraham W. M. 《Journal of applied physiology》1995,79(6):1966-1970
192.
Corticotropin-releasing hormone (CRH) has been shown to be a central mediator for most, if not all, stress-induced responses. Since stressful stimuli may decrease hypothalamic tuberoinfundibular and tuberohypophysial dopaminergic neuronal activities, we aimed to determine whether CRH is involved. Using central administration of various doses of ovine CRH (oCRH; 1, 3 and 10 µg/rat) into the lateral cerebroventricle of either male or female rats, the neurochemical changes in various parts of the central nervous system, including the hypothalamus, were determined by high-performance liquid chromatography at various times after the injection (30, 60, 120 and 240 min). The concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC) and 3-methoxy-4-hydroxy-phenylethyleneglycol (MHPG), two major metabolites of dopamine and norepinephrine, respectively, in discrete brain regions were used as indices for catecholaminergic neuron activity. Plasma corticosterone levels increased significantly after all doses of oCRH and at all time points studied. oCRH also exerted significant stimulatory effects on noradrenergic neuron terminals in the frontal cortex, and on dopaminergic neuron terminals in the nucleus accumbens, hypothalamic paraventricular and periventricular nuclei, and intermediate pituitary lobe. Dopaminergic neuron terminals in the median eminence and the neural lobe of the pituitary, however, were not affected. There was no major difference in the responses between male and female rats. We conclude that CRH has a differential effect on central catecholaminergic neurons. 相似文献
193.
A new orphan member of the nuclear hormone receptor superfamily that interacts with a subset of retinoic acid response elements. 总被引:18,自引:5,他引:13
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M Baes T Gulick H S Choi M G Martinoli D Simha D D Moore 《Molecular and cellular biology》1994,14(3):1544-1552
We have identified and characterized a new orphan member of the nuclear hormone receptor superfamily, called MB67, which is predominantly expressed in liver. MB67 binds and transactivates the retinoic acid response elements that control expression of the retinoic acid receptor beta 2 and alcohol dehydrogenase 3 genes, both of which consist of a direct repeat hexamers related to the consensus AGGTCA, separated by 5 bp. MB67 binds these elements as a heterodimer with the 9-cis-retinoic acid receptor, RXR. However, MB67 does not bind or activate other retinoic acid response elements with alternative hexamer arrangements or any of several other wild-type and synthetic hormone response elements examined. The transactivation of retinoic acid response elements by MB67 is weaker than that conferred by the retinoic acid receptors but does not require the presence of all-trans retinoic acid, 9-cis-retinoic acid, or any exogenously added ligand. We propose that MB67 plays an important role in the complex network of proteins that govern response to retinoic acid and its metabolites. 相似文献
194.
Double or Nothing: A Drosophila Mutation Affecting Meiotic Chromosome Segregation in Both Females and Males 总被引:5,自引:0,他引:5
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We describe a Drosophila mutation, Double or nothing (Dub), that causes meiotic nondisjunction in a conditional, dominant manner. Previously isolated mutations in Drosophila specifically affect meiosis either in females or males, with the exception of the mei-S332 and ord genes which are required for proper sister-chromatid cohesion. Dub is unusual in that it causes aberrant chromosome segregation almost exclusively in meiosis I in both sexes. In Dub mutant females both nonexchange and exchange chromosomes undergo nondisjunction, but the effect of Dub on nonexchange chromosomes is more pronounced. Dub reduces recombination levels slightly. Multiple nondisjoined chromosomes frequently cosegregate to the same pole. Dub results in nondisjunction of all chromosomes in meiosis I of males, although the levels are lower than in females. When homozygous, Dub is a conditional lethal allele and exhibits phenotypes consistent with cell death. 相似文献
195.
Felicity Z. Watts Neil Butt Philip Layfield Jesse Machuka Julian F. Burke Anthony L. Moore 《Plant molecular biology》1994,26(1):445-451
An Arabidopsis thaliana gene (UBC6) encoding a homologue to ubiquitin-conjugating enzymes has been isolated which is capable of encoding a protein of 183 amino acids of ca. 21 kDa. Northern analysis indicates that the gene is expressed in flowers, seeds and, to a somewhat lesser extent, in 10-day seedlings but not in mature leaves, callus and pre-flowering plants. This pattern of expression is confirmed using transgenic Arabidopsis plants containing a UBC6 promoter-GUS gene fusion construct. These plants displey GUS activity in mature anthers prior to dehiscence, in developing embryos, sepals and the style after pollination. 相似文献
196.
The nucleotide sequence encoding the penton base integrin-binding domains of several human adenoviruses was obtained by homology PCR. Each of the penton base proteins contains a conserved Arg-Gly-Asp (RGD) sequence that is predicted to lie at the apex of two extended alpha helices. The penton base RGD domain promotes efficient infection of host cells by multiple adenovirus serotypes via interaction with alpha v integrins, thus indicating that alpha v integrins play a central role in the entry of adenoviruses into host cells. 相似文献
197.
Donald H. Williamson Malcolm J. Gardner Peter Preiser Daphne J. Moore Kaveri Rangachari Robert J. M. Wilson 《Molecular & general genetics : MGG》1994,243(2):249-252
In common with other Apicomplexan parasites, Plasmodium falciparum carries two extrachromosomal DNAs, one of which, the 6 kb element, is undoubtedly mitochondrial. The second, generally referred to as the 35 kb circle, is of unknown provenance, but the nature and organization of its genetic content makes a mitochondrial association unlikely and the molecule has features reminiscent of plastid genomes. We now report the occurrence on the circle of an open reading frame specifying a predicted 470 amino acid protein that shares more than 50% identity with a gene currently known only on the plastome of red algae. This high degree of conservation confirms the 35 kb circle's plastid ancestry, and we speculate that it may have originated from the rhodoplast of an ancient red algal endosymbiont in the progenitor of the Apicomplexa. 相似文献
198.
W. Y. Cheung T. A. Money S. Abbo K. M. Devos M. D. Gale G. Moore 《Molecular & general genetics : MGG》1994,245(3):349-354
A family of related sequences associated with (TTTAGGG)
n
repeats has been cloned from the wheat cultivar Chinese Spring. These sequences reveal a high level of polymorphism between wheat varieties when used as restriction fragment length polymorphism (RFLP) probes. Although this family of sequences contains motifs homologous to the repeats in the telomeres of wheat, they are located at interstitial sites on wheat chromosomes. 相似文献
199.
Graham J. Moore Renee C. Ganter John M. Matsoukas John Hondrelis George Agelis Klemoenis Barlos Scott Wilkinson John Sandall Patrick Fowler 《Journal of molecular recognition : JMR》1994,7(4):251-256
A triad of interacting group (TyrOH? His$ \underline\ominus$O2C) in angiotensin II (ANG II) has been postulated to create the tyrosinate anion pharmacophore (tyanophore) responsible for receptor activation/triggering (Biochim. Biophys. Acta 1991, 1065, 21). In the present study we investigated the effects on bioactivity of substituting the Tyr4 residue in [Sar1]ANG II with other anionic or electronegative amino acids, and with a number of aromatic amino acids lacking a hydroxyl group. [Sar1 Nva(δ-OH)4]ANG II, [Sar1 Nva(δ-OCH3)4]ANG II, [Sar1 Met4]ANG II, [Sar1 Gln4]ANG II, [Sar1 Glu4]ANG II and [Sar1 DL -Alg4]ANG II had agonist activities in the rat isolated uterus assay of 4, 3, 19, 10, > 0.1 and > 0.1%, respectively, of that of ANG II. [Sar1 Nal4]ANG II, [Sar1 Pal4]ANG II, [Sar1 DL -Phg(4′-F)4]ANG II, [Sar1 Phe(4′-F)4]ANG II, [Sar1 Phe(F5)4]ANG II and [Sar1 His4]ANG II had agonist activities of 4.5, 7, < 0.1, 0.2, 1 and 0.6%, respectively. All peptides investigated were devoid of measurable antagonist activity except [Sar1] Phe(4′-F)4 ANG II (pA2 = 7.7). These findings illustrate that anionic or electronegative aliphatic side chains replacing tyrosinate at position 4 can partially activate the angiotension receptor. For ANG II analogues containing an aromatic amino acid other than Tyr at position 4, ligand binding and agonist activity are not dependent on the electronegativity or dipole moment of the aromatic ring, or on the ability of the 4′ ring substituent to accept a proton. Modelling based on ab initio calculations of aromatic ring multipoles illustrate that the apparent binding affinity (PA2) of ANG II analogues is associated with a perpendicular electrostatic interaction of the position 4 aromatic ring with a receptor-based group. In addition, intramolecular interactions providing for the conformation of the ligand as it approaches its receptor appear to have a role in determining agonist vs antagonist activity. 相似文献
200.
Common structural features of the luxF protein and the subunits of bacterial luciferase: evidence for a (beta alpha)8 fold in luciferase.
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S. A. Moore M. N. James 《Protein science : a publication of the Protein Society》1994,3(11):1914-1926
The amino acid sequence identity and potential structural similarity between the subunits of bacterial luciferase and the recently determined structure of the luxF molecule are examined. The unique beta/alpha barrel fold found in luxF appears to be conserved in part in the luciferase subunits. From secondary structural predictions of both luciferase subunits, and from structural comparisons between the protein product of the luxF gene, NFP, and glycolate oxidase, we propose that it is feasible for both luciferase subunits to adopt a (beta alpha)8 barrel fold with at least 2 excursions from the (beta alpha)8 topology. Amino acids conserved between NFP and the luciferase subunits cluster together in 3 distinct "pockets" of NFP, which are located at hydrophobic interfaces between the beta-strands and alpha-helices. Several tight turns joining the C-termini of beta-strands and the N-termini of alpha-helices are found as key components of these conserved regions. Helix start and end points are easily demarcated in the luciferase subunit protein sequences; the N-cap residues are the most strongly conserved structural features. A partial model of the luciferase beta subunit from Photobacterium leiognathi has been built based on our crystallographically determined structure of luxF at 1.6 A resolution. 相似文献