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11.
Elisabet Font Mercedes Sitges Fausto G. Hegardt 《Biochemical and biophysical research communications》1982,105(2):705-710
Rat liver homogeneous 32P-labeled hydroxy methylglutaryl coenzyme A reductase, was treated independently with CNBr and trypsin and the resulting [32P]phosphopeptides were analyzed by disc gel electrophoresis. CNBr treatment produced only one 32P-fragment of Mr 18,000. The time course of trypsin hydrolysis initially showed the appearance of some phosphopeptides, which were lately converted in two phosphopeptides of low Mr. These results provide direct support for the concept that hydroxy methyl glutaryl coenzyme A reductase kinase solubilized from microsomes phosphorylates only two sites or set of sites in the reductase molecule. 相似文献
12.
Transforming growth factor-beta (TGF-beta) isoforms in rat liver regeneration: messenger RNA expression and activation of latent TGF-beta. 总被引:7,自引:0,他引:7
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S B Jakowlew J E Mead D Danielpour J Wu A B Roberts N Fausto 《Molecular biology of the cell》1991,2(7):535-548
Expression of transforming growth factor-beta s (TGF-beta s) 1-3 was studied in normal liver and during liver regeneration after partial hepatectomy in the rat to determine whether each of these isoforms might be involved in hepatocyte growth in vivo. Expression of the mRNAs for all three TGF-beta isoforms increases in the regenerating liver. In addition, the levels of expression of the mRNAs for several extracellular matrix proteins, including fibronectin, vitronectin, laminin, and collagen, also increase in the regenerating liver. Immunohistochemical staining analysis shows a similar distribution of all three TGF-beta s in normal and regenerating liver; however, in both tissues, the level of expression of TGF-beta 1 is 8- to 10-fold higher than that of TGF-beta 2 as determined by sandwich enzyme-linked immunosorbent assay. Expression of all three TGF-beta mRNAs is restricted to liver nonparenchymal cells. Although hepatocytes from normal and regenerating livers do not synthesize TGF-beta, they are sensitive to inhibition of growth by all three TGF-beta isoforms. Hepatocytes from regenerating livers are capable of activating latent TGF-beta 1 complexes in vitro, whereas normal hepatocytes are not. The different TGF-beta isoforms may function in an inhibitory paracrine mechanism that is activated during liver regeneration and may also regulate the synthesis of extracellular matrix components in the regenerating liver. 相似文献
13.
Subunit structure of dihydrolipoamide acetyltransferase component of pyruvate dehydrogenase complex from bovine kidney 总被引:2,自引:0,他引:2
The pyruvate dehydrogenase complex has been isolated from bovine kidney mitochondria under special anti-proteolytic conditions yielding preparations with a specific activity of up to 20 U/mg protein. Dihydrolipoamide acetyltransferase resolved from the complex was subjected to limited proteolysis resulting in the formation of two major fragments with apparent molecular weights of 36000 and 28000. The fragments were isolated by extraction from dodecyl sulfate polyacrylamide gels and were both shown to possess enzymatic activity for acetyl transfer. Acetylation studies indicated that each fragment contains one protein-bound lipoyl group. It is concluded that the kidney dihydrolipoamide acetyltransferase subunit consists of two homologous if not identical domains. A model is suggested where the acetyltransferase core of the mammalian pyruvate dehydrogenase complex is made up of 30 polypeptide chains whose 60 domains could be arranged in pentagonal dodecahedron symmetry quite similar as proposed for the 60 subunit structure of the acetyltransferase core. 相似文献
14.
31P NMR chemical shifts of salts of adenosine 5′-triphosphate and diphosphate: ATPH2?22(Me4N+) · H2O, ATPH2?22 Na+ · 3.5 H2O, ATPH2?2Mg2+ · 4 H2O, ATPH2?2Ca2+ · 2 H2O, ADPH2?2(Me4N+) · H2O and ADPH2?Mg2+ · 4 H2O have been measured in 0.02 M 2H2O solutions at 145.7 MHz (22° C) at constant p2H values (8.20 and 6.20). The results are compared with those obtained from salts of adenosine 5′-monophosphate and other simpler phosphomonoesters, e.g. AMP2?2(Me4N+), AMP2?Mg2+, AMPH?Me4N+ and (AMPH?)2Mg2+. It is concluded that the effects exerted by Mg2+ and Ca2+ on the 31P NMR shifts of dipoly- and tripolyphosphates relative to monovalent cations are due mainly to changes in conformation of the polyphosphate chain rather than to purely electronic factors associated with the binding of divalent cations to the phospho-oxyanions. The data are consistent with the existence of the following complexes at p2H 8.20: (MgPαPβ)ADP? and (MgPαPγ)ATP2?af (MgPαPβ)ATP2?af (MgPβPγ)ATP2? with the latter equilibrium relatively fast in the NMR time scale. Monoprotonation of the terminal phosphate appears to weaken the Mg2+-polyphosphate binding, particularly at Pβ of MgADPH and at Pβ and Pγ of MgATPH?. The Mg2+-polyphosphate binding weakens further at p2H 3.70, i.e. in MgATPH2. Possible implications of the results in the mechanism of actomyosin Mg2+-ATPase in muscle contraction are discussed. 相似文献
15.
T H Nahm S W Lee A Fausto Y Sonn L V Avioli 《Biochemical and biophysical research communications》1979,89(2):396-402
Serum and hepatic 25-hydroxyvitamin D (25OHD), and serum calcium, phosphate, 25OHD3 binding capacity and binding affinity were measured in male and female trout. Both serum and hepatic 25OHD levels are decreased in female trout with elevations in protein bound calcium and phosphate. Whereas the apparent dissociation constant (Kd) for serum binding of 25OHD3 of 1.0–2.0 × 10?9M is similar in males and females, the 25OHD3 binding capacity of hypercalcemic spawning trout (1.39 × 10?7M) is significantly less than that of male fish (1.88 × 10?7M). At circulating serum concentrations of 25OHD which average 9.5 × 10?9M only 5–7% of trout serum 25OHD binding sites are occupied. 相似文献
16.
17.
Verena Gswein Carla Rodrigues Jos D. Silvestre Fausto Freire Guillaume Habert Jakob Knig 《Journal of Industrial Ecology》2020,24(1):178-192
The built environment is the largest single emitter of CO2 and an important consumer of energy. Much research has gone into the improved efficiency of building operation and construction products. Life Cycle Assessment (LCA) is commonly used to assess existing buildings or building products. Classic LCA, however, is not suited for evaluating the environmental performance of developing technologies. A new approach, anticipatory LCA (a‐LCA), promises various advantages and can be used as a design constraint during the product development stage. It helps overcome four challenges: (i) data availability, (ii) stakeholder inclusion, (iii) risk assessment, and (iv) multi‐criteria problems. This article's contribution to the line of research is twofold: first, it adapts the a‐LCA approach for construction‐specific purposes in theoretical terms for the four challenges. Second, it applies the method to an innovative prefabricated modular envelope system, the CleanTechBlock (CTB), focusing on challenge (i). Thirty‐six CTB designs are tested and compared to conventional walls. Inclusion of technology foresight is achieved through structured scenario analysis. Moreover, challenge (iv) is tackled through the analysis of different environmental impact categories, transport‐related impacts, and thickness of the wall assemblies of the CTB. The case study results show that optimized material choice and product design is needed to reach the lowest environmental impact. Methodological findings highlight the importance of context‐specific solutions and the need for benchmarking new products. 相似文献
18.
Leonardo Ancillotto Luciano Bosso Sonia Smeraldo Emiliano Mori Giuseppe Mazza Matthias Herkt Andrea Galimberti Fausto Ramazzotti Danilo Russo 《Ecology and evolution》2020,10(12):5785-5800
Because of the high risk of going unnoticed, cryptic species represent a major challenge to biodiversity assessments, and this is particularly true for taxa that include many such species, for example, bats. Long‐eared bats from the genus Plecotus comprise numerous cryptic species occurring in the Mediterranean Region and present complex phylogenetic relationships and often unclear distributions, particularly at the edge of their known ranges and on islands. Here, we combine Species Distribution Models (SDMs), field surveys and molecular analyses to shed light on the presence of a cryptic long‐eared bat species from North Africa, Plecotus gaisleri, on the islands of the Sicily Channel, providing strong evidence that this species also occurs in Europe, at least on the islands of the Western Mediterranean Sea that act as a crossroad between the Old Continent and Africa. Species Distribution Models built using African records of P. gaisleri and projected to the Sicily Channel Islands showed that all these islands are potentially suitable for the species. Molecular identification of Plecotus captured on Pantelleria, and recent data from Malta and Gozo, confirmed the species' presence on two of the islands in question. Besides confirming that P. gaisleri occurs on Pantelleria, haplotype network reconstructions highlighted moderate structuring between insular and continental populations of this species. Our results remark the role of Italy as a bat diversity hotspot in the Mediterranean and also highlight the need to include P. gaisleri in European faunal checklists and conservation directives, confirming the usefulness of combining different approaches to explore the presence of cryptic species outside their known ranges—a fundamental step to informing conservation. 相似文献
19.
Ana Marcia Escocard de Azevedo Manhaes Fausto Andres Ortiz-Morea Ping He Libo Shan 《植物学报(英文版)》2021,63(1):79-101
As sessile organisms, plants are exposed to pathogen invasions and environmental fluctuations. To overcome the challenges of their surroundings, plants acquire the potential to sense endogenous and exogenous cues, resulting in their adaptability. Hence, plants have evolved a large collection of plasma membrane-resident receptors, including RECEPTOR-LIKE KINASEs(RLKs) and RECEPTOR-LIKE PROTEINs(RLPs) to perceive those signals and regulate plant growth,development, and immunity. The ability of RLKs and RLPs to recognize distinct ligands relies on diverse categories of extracellular domains evolved. Co-regulatory receptors are often required to associate with RLKs and RLPs to facilitate cellular signal transduction. RECEPTOR-LIKE CYTOPLASMIC KINASEs(RLCKs) also associate with the complex, bifurcating the signal to key signaling hubs, such as MITOGEN-ACTIVATED PROTEIN KINASE(MAPK) cascades, to regulate diverse biological processes. Here, we discuss recent knowledge advances in understanding the roles of RLKs and RLPs in plant growth, development, and immunity, and their connection with co-regulatory receptors, leading to activation of diverse intracellular signaling pathways. 相似文献
20.
Tatiana Aparecida Voltolin Manolo Penitente Bruna Bueno Mendon?a José Augusto Senhorini Fausto Foresti Fábio Porto-Foresti 《Genetics and molecular biology》2013,36(3):347-352
The family Prochilodontidae is considered a group with well conserved chromosomes characterized by their number, morphology and banding patterns. Thence, our study aimed at accomplishing a cytogenetic analysis with conventional methods (Giemsa staining, silver staining of the nucleolus organizer regions-AgNOR, and C-banding) and fluorescence in situ hybridization (FISH) with 18S and 5S ribosomal DNA probes in five species of the Prochilodus genus (Prochilodus argenteus, Prochilodus brevis, Prochilodus costatus, Prochilodus lineatus and Prochilodus nigricans) collected from different Brazilian hydrographic basins. The results revealed conservatism in chromosome number, morphology, AgNORs 18S and 5S rDNAs location and constitutive heterochromatin distribution patterns. The minor differences observed in this work, such as an Ag-NOR on a P. argenteus chromosome and a distinct C-banding pattern in P. lineatus, are not sufficient to question the conservatism described for this group. Future work using repetitive DNA sequences as probes for FISH will be interesting to further test the cytogenetic conservatism in Prochilodus. 相似文献