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121.
Two anion transporters AtClCa and AtClCe fulfil interconnecting but not redundant roles in nitrate assimilation pathways 总被引:1,自引:0,他引:1
122.
Oliva Jurado Alfonso Albacete M. Carmen Martínez-Ballesta Micaela Carvajal Francisco Pérez-Alfocea Ian C. Dodd M. Remedios Romero-Aranda 《Physiologia plantarum》2009,137(1):36-43
The tos1 (tomato osmotically sensitive) mutant, isolated from an in vitro screen of root growth during osmotic stress, was less sensitive to exogenous ABA, but accumulated more ABA under osmotic stress than WT plants. We assessed growth and water relations characteristics of hydroponically grown tos1 seedlings (in the absence of osmotic stress) at low and high evaporative demands. Growth of tos1 was severely inhibited at both high and low evaporative demands. Twenty DAS, WT and tos1 genotypes had a similar leaf water and turgor potential, but mature tos1 plants (45 day old) showed a significant diurnal loss of leaf turgor, with recovery overnight. Increased evaporative demand increased turgor loss of tos1 plants. High evaporative demand at the beginning of the day decreased stomatal conductance of tos1, without diurnal recovery, thus whole plant transpiration was decreased. De-topped tos1 seedlings showed decreased root hydraulic conductance and had a 1.4-fold increase in root ABA concentration. Impaired root function of tos1 plants failed to meet transpirational water demand and resulted in shoot turgor loss, stomatal closure and growth inhibition. 相似文献
123.
The zinc-coordinated protein motifs known as RING-finger domains, present on a class of ubiquitin ligases (E3's), recruit ubiquitin-conjugating enzymes (E2s), tethering them to substrate proteins for covalent modification with ubiquitin. Each RING-finger domain can recruit different E2s, and these interactions are frequently selective, in that certain RING-finger domains associate preferentially with certain E2s. This selectivity acquires particular biological relevance when the recruited E2s exert specialized functions. We have explored the determinants that specify the presence or absence of experimentally detectable interaction between two RING-finger domains, those on RNF11 and RNF103, and two E2s, UBC13, a specialized E2 that catalyzes ubiquitin chain elongation through Lys63 of ubiquitin, and UbcH7, which mediates polyubiquitylation through Lys48. Through the iterative use of computational predictive tools and experimental validations, we have found that these interactions and their selectivity are partly governed by the combinations of electrostatic interactions linking specific residues of the contact interfaces. Our analysis also predicts that the main determinants of selectivity of these interactions reside on the RING-finger domains, rather than on the E2s. The application of some of these rules of interaction selectivity has permitted us to experimentally manipulate the selectivity of interaction of the RING-finger domain-E2 pairs under study. 相似文献
124.
Eduardo Gusmão Pereira Marco Antonio Oliva Kacilda Naomi Kuki José Cambraia 《Trees - Structure and Function》2009,23(2):277-285
The effect of iron solid particulate matter (SPMFe) deposited onto soil and leaves on photosynthesis and oxidative stress was evaluated in Clusia hilariana, a CAM tropical tree of high occurrence in Brazilian restingas. Significant increases in iron content were found in plants
exposed to SPMFe applied onto leaf and soil surfaces. However, only the application of SPMFe on leaves of C. hilariana caused significant reductions in some evaluated characteristics such as photosynthetic rate, stomatal conductance, transpiration,
organic acid accumulation, potential quantum yield of PSII, and changes in daily CAM photosynthesis pattern. Increase in relative
membrane permeability and reduction in catalase and superoxide dismutase activities in the leaves of plants exposed to SPMFe also were observed; however, lipid peroxidation did not change. These responses seem to be due to the combination of physical
effects such as increase of leaf temperature, reduction in light absorption, obstruction of stomatal pores, and biochemical
effects triggered by oxidative stress. 相似文献
125.
Orlandi A Oliva F Taurisano G Candi E Di Lascio A Melino G Spagnoli LG Tarantino U 《Amino acids》2009,36(4):755-763
Osteoarthritis is a progressive joint disease characterized by cartilage degradation and bone remodeling. Transglutaminases
catalyze a calcium-dependent transamidation reaction that produces covalent cross-linking of available substrate glutamine
residues and modifies the extracellular matrix. Increased transglutaminases-mediated activity is reported in osteoarthritis,
but the relative contribution of transglutaminases-2 (TG2) is uncertain. We describe TG2 expression in human femoral osteoarthritis
and in wild-type and homozygous TG2 knockout mice after surgically-induced knee joint instability. Increased TG2 levels were
observed in human and wild-type murine osteoarthritic cartilage compared to the respective controls. Histomorphometrical but
not X-ray investigation documented in osteoarthritic TG2 knockout mice reduced cartilage destruction and an increased osteophyte
formation compared to wild-type mice. These differences were associated with increased TGFβ-1 expression. In addition to confirming
its important role in osteoarthritis development, our results demonstrated that TG2 expression differently influences cartilage
destruction and bone remodeling, suggesting new targeted TG2-related therapeutic strategies. 相似文献
126.
Tomás-Pejó E García-Aparicio M Negro MJ Oliva JM Ballesteros M 《Bioresource technology》2009,100(2):890-895
This study was aimed to study the effect of commercial cellulases (Celluclast 1.5 LFG) on Kluyveromyces marxianus CECT 10875 growth and ethanol production in SSF processes. Preliminary tests carried out in glucose (50 g/L) fermentation medium showed that high enzyme amounts (2.5-3.5 FPU/mL) could cause a negative effect on K. marxianus growth rate and viable cells number. However, the maximum ethanol production was not affected and about 86% of the theoretical (22 g/L) was reached in all cases independently of the enzyme dosage. In SSF experiments, cell viability was always affected by enzyme loading. Nevertheless, slight differences observed on cell viability during glucose fermentation processes with the detected concentrations of the additives did not justify the negative effect observed in SSF experiments. 相似文献
127.
The relationships between testosterone concentrations in male African rhinoceros and the presence of conspecific males and females were investigated. Serum testosterone concentrations were measured using enzyme-linked immunoassay (EIA) in 37 male black rhinoceros (Diceros bicornis) and 21 male white rhinoceros (Ceratotherium simum) housed at 37 institutions in the USA. Testosterone concentrations in both black (n = 37) and white (n = 21) rhinoceros males rose with increasing numbers of females present (P < 0.05). Average testosterone concentrations also rose with an increased number of conspecific males (n = 34) in black rhinoceros (P < 0.05). However, no specific pattern was found among male white rhinoceros housed with other males. We inferred that introduction of females to a male may play an important role in stimulating libido and spermatogenesis. The similar response of black rhinoceros and white rhinoceros to increased numbers of females suggested that, at least historically, herd structure for blacks may have been more similar to whites than previously realized, and should be investigated further. 相似文献
128.
Renato F. Freitas Igor M. Prokopczyk Aderson Zottis Glaucius Oliva Adriano D. Andricopulo Maria Teresa S. Trevisan Wagner Vilegas Maria Goretti V. Silva Carlos A. Montanari 《Bioorganic & medicinal chemistry》2009,17(6):2476-2482
Based on its essential role in the life cycle of Trypanosoma cruzi, the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH) has been considered a promising target for the development of novel chemotherapeutic agents for the treatment of Chagas’ disease. In the course of our research program to discover novel inhibitors of this trypanosomatid enzyme, we have explored a combination of structure and ligand-based virtual screening techniques as a complementary approach to a biochemical screening of natural products using a standard biochemical assay. Seven natural products, including anacardic acids, flavonoid derivatives, and one glucosylxanthone were identified as novel inhibitors of T. cruzi GAPDH. Promiscuous inhibition induced by nonspecific aggregation has been discarded as specific inhibition was not reversed or affected in all cases in the presence of Triton X-100, demonstrating the ability of the assay to find authentic inhibitors of the enzyme. The structural diversity of this series of promising natural products is of special interest in drug design, and should therefore be useful in future medicinal chemistry efforts aimed at the development of new GAPDH inhibitors having increased potency. 相似文献
129.
Francesco Oliva Loredana Zocchi Eleonora Candi Gerry Melino Umberto Tarantino 《Biochemical and biophysical research communications》2009,379(4):887-891
The ethiopathogenesis of rotator cuff disease remains poorly understood. Many studies advocate the importance of extra cellular matrix for the homeostasis of connective tissue. Transglutaminase enzymes family has been studied in the context of connective tissue formation and stabilisation. Here, we investigated transglutaminases expression pattern in biopsies of normal and injured supraspinatus tendons of human shoulders and in the Achilles tendons of transglutaminase 2 knock-out and wild-type mice. Our results show that different transglutaminase family members are differentially expressed in human and mouse tendons, and that transglutaminase 2 is down-regulated at mRNA and protein levels upon human supraspinatus tendon ruptures. 相似文献
130.
Ney Ribeiro Leite Renata Krogh Wei Xu Yuko Ishida Jorge Iulek Walter S. Leal Glaucius Oliva 《PloS one》2009,4(11)