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101.
Paumard P Vaillier J Napias C Arselin G Brèthes D Graves PV Velours J 《Biochemistry》2000,39(14):4199-4205
The topology of subunit i, a component of the yeast F(o)F(1)-ATP synthase, was determined by the use of cysteine-substituted mutants. The N(in)-C(out) orientation of this intrinsic subunit was confirmed by chemical modification of unique cysteine residues with 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid. Near-neighbor relationships between subunit i and subunits 6, f, g, and d were demonstrated by cross-link formation following sulfhydryl oxidation or reaction with homobifunctional and heterobifunctional reagents. Our data suggest interactions between the unique membrane-spanning segment of subunit i and the first transmembranous alpha-helix of subunit 6 and a stoichiometry of 1 subunit i per complex. Cross-linked products between mutant subunits i and proteins loosely bound to the F(o)F(1)-ATP synthase suggest that subunit i is located at the periphery of the enzyme and interacts with proteins of the inner mitochondrial membrane that are not involved in the structure of the yeast ATP synthase. 相似文献
102.
103.
Inflammation-associated lysyl oxidase protein expression in vivo, and modulation by FGF-2 plus IGF-1
P. C. Trackman Rudolph J. Graham Howard K. Bittner David L. Carnes James A. Gilles Dana T. Graves 《Histochemistry and cell biology》1998,110(1):9-14
Lysyl oxidase is the extracellular enzyme that catalyzes oxidative deamination of peptidyl-lysine residues in elastin precursors,
and lysine and hydroxylysine residues in collagen precursors to form peptidyl-aldehydes. These aldehydes then spontaneously
condense to crosslink collagen and elastin and thereby allow the formation of a mature and functional extracellular matrix.
In the present study, cryosections made from aseptic immune-induced periapical lesions experimentally generated in laboratory
rats were examined by immunohistochemistry to investigate whether lysyl oxidase protein expression is altered in inflamed
oral tissues. Periapical lesions are experimentally induced endodontic lesions of tooth roots. In addition, the effect of
administration of a mixture of fibroblast growth factor (FGF)-2 and insulin-like growth factor (IGF)-1 into these lesions
on lysyl oxidase expression was determined. Lysyl oxidase expression was found to be increased in non-mineralized connective
tissue adjacent to inflamed lesions. Morphometric analyses indicated that maximum lysyl oxidase expression occurred at a discrete
distance from the lesion not exceeding 350 μm from the inflammatory cells. Staining was associated with mesenchymal cells
with a fibroblastic morphology. No lysyl oxidase staining was found near teeth where no lesion was induced. Application of
a mixture of FGF-2 and IGF-1 resulted in a further twofold increase in lysyl oxidase expression. These results provide a new
in vivo model to study lysyl oxidase regulation, and suggest that inflammatory cells may control lysyl oxidase expression
in oral tissues, possibly by a mechanism involving secretion of cytokines and other factors, probably contributing to the
regulation of extracellular matrix accumulation.
Accepted: 19 December 1998 相似文献
104.
105.
Suneeth F. Mathew Caillan Crowe-McAuliffe Ryan Graves Tony S. Cardno Cushla McKinney Elizabeth S. Poole Warren P. Tate 《PloS one》2015,10(3)
HIV-1 utilises −1 programmed ribosomal frameshifting to translate structural and enzymatic domains in a defined proportion required for replication. A slippery sequence, U UUU UUA, and a stem-loop are well-defined RNA features modulating −1 frameshifting in HIV-1. The GGG glycine codon immediately following the slippery sequence (the ‘intercodon’) contributes structurally to the start of the stem-loop but has no defined role in current models of the frameshift mechanism, as slippage is inferred to occur before the intercodon has reached the ribosomal decoding site. This GGG codon is highly conserved in natural isolates of HIV. When the natural intercodon was replaced with a stop codon two different decoding molecules—eRF1 protein or a cognate suppressor tRNA—were able to access and decode the intercodon prior to −1 frameshifting. This implies significant slippage occurs when the intercodon is in the (perhaps distorted) ribosomal A site. We accommodate the influence of the intercodon in a model of frame maintenance versus frameshifting in HIV-1. 相似文献
106.
Elaine W. Chong Yuanyuan Wang Liubov D. Robman Khin Zaw Aung Galina A. Makeyeva Graham G. Giles Stephen Graves Flavia M. Cicuttini Robyn H. Guymer 《PloS one》2015,10(9)
Osteoarthritis is the leading cause of total hip replacement, accounting for more than 80% of all total hip replacements. Emerging evidence suggests that osteoarthritis has a chronic inflammatory component to its pathogenesis similar to age-related macular degeneration. We evaluated the association between age-related macular degeneration and total hip replacement as proxy for severe osteoarthritis or fractured neck of femur in the Melbourne Collaborative Cohort Study. 20,744 participants had complete data on both age-related macular degeneration assessed from colour fundus photographs taken during 2003–2007 and total hip replacement. Total hip replacements due to hip osteoarthritis and fractured neck of femur during 2001–2011 were identified by linking the cohort records to the Australian Orthopedic Association National Joint Replacement Registry. Logistic regression was used to examine the association between age-related macular degeneration and risk of total hip replacement due to osteoarthritis and fracture separately, adjusted for confounders. There were 791 cases of total hip replacement for osteoarthritis and 102 cases of total hip replacement due to fractured neck of femur. After adjustment for age, sex, body mass index, smoking, and grouped country of birth, intermediate age-related macular degeneration was directly associated with total hip replacement for osteoarthritis (odds ratio 1.22, 95% CI 1.00–1.49). Late age-related macular degeneration was directly associated with total hip replacement due to fractured neck of femur (odds ratio 5.21, 95% CI2.25–12.02). The association between intermediate age-related macular degeneration and an increased 10-year incidence of total hip replacement due to osteoarthritis suggests the possibility of similar inflammatory processes underlying both chronic diseases. The association of late age-related macular degeneration with an increased 10-year incidence of total hip replacement due to fractured neck of femur may be due to an increased prevalence of fractures in those with poor central vision associated with the late complications of age-related macular degeneration. 相似文献
107.
108.
Brian J. Dewar Kayvan Keshari Rex Jeffries Petras Dzeja Lee M. Graves Jeffrey M. Macdonald 《Metabolomics : Official journal of the Metabolomic Society》2010,6(3):439-450
The goal of this study was to examine metabolic differences between a novel chronic myelogenous leukemic (CML) cell line,
MyL, and a sub-clone, MyL-R, which displays enhanced resistance to the targeted Bcr-Abl tyrosine kinase inhibitor imatinib.
1H nuclear magnetic resonance (NMR) spectroscopy was carried out on cell extracts and conditioned media from each cell type.
Both principal component analysis (PCA) and specific metabolite identification and quantification were used to examine metabolic
differences between the cell types. MyL cells showed enhanced glucose removal from the media compared to MyL-R cells with
significant differences in production rates of the glycolytic end-products, lactate and alanine. Interestingly, the total
intracellular creatine pool (creatine + phosphocreatine) was significantly elevated in MyL-R compared to MyL cells. We further
demonstrated that the MyL-R cells converted the creatine to phosphocreatine using non-invasive monitoring of perfused alginate-encapsulated
MyL-R and MyL cells by in vivo 31P NMR spectroscopy and subsequent HPLC analysis of extracts. Our data demonstrated a clear difference in the metabolite profiles
of drug-resistant and sensitive cells, with the biggest difference being an elevation of creatine metabolites in the imatinib-resistant
MyL-R cells. 相似文献
109.
Ronda R. Graves Amy C. Lupo Daniel J. Wescott Deborah L. Cunningham 《Journal of human evolution》2010,59(5):542-554
For over twenty years, the young, male Homo erectus specimen KNM-WT 15000 has been the focus of studies on growth and development, locomotion, size, sexual dimorphism, skeletal morphology, and encephalization, often serving as the standard for his species. Prior research on KNM-WT 15000 operates under the assumption that H. erectus experienced a modern human life history, including an adolescent growth spurt. However, recent fossil discoveries, improvements in research methods, and new insights into modern human ontogeny suggest that this may not have been the case. In this study, we examine alternative life history trajectories in H. erectus to re-evaluate adult stature estimates for KNM-WT 15000. We constructed a series of hypothetical growth curves by modifying known human and chimpanzee curves, calculating intermediate growth velocities, and shifting the age of onset and completion of growth in stature. We recalculated adult stature for KNM-WT 15000 by increasing stature at death by the percentage of growth remaining in each curve. The curve that most closely matches the life history events experienced by KNM-WT 15000 prior to death indicates that growth in this specimen would have been completed by 12.3 years of age. These results suggest that KNM-WT 15000 would have experienced a growth spurt that had a lower peak velocity and shorter duration than the adolescent growth spurt in modern humans. As a result, it is likely that KNM-WT 15000 would have only attained an adult stature of 163 cm (∼5′4″), not 185 cm (∼6′1″) as previously reported. KNM-WT 15000's smaller stature has important implications for evolutionary scenarios involving early genus Homo. 相似文献
110.
Cell cycle studies, using PLM analysis, were carried out on a mouse-Chinese hamster cell hybrid and its derivatives which stably retained all parental chromosomes during the year of study. Parameter estimates were obtained from the PLM curves, using conjugate gradient curve fitting procedures. The hybrid initially grew very slowly, and all phases (especially G1) were longer than those of either parent. During propagation, mean generation time decreased progressively, and the phase times approached those of the mouse parent (which had the longer G1 and S). DNA replication could be scored separately in mouse and hamster chromosome sets; initially termination was highly asynchronous, but during growth asynchrony was progressively reduced as DNA synthesis in the hamster set was prolonged. We conclude that cell hybrids may undergo progressive modifications of the cell cycle, even in the absence of significant chromosome segregation, and suggest that such changes may at least partly account for the great variety of relationships between the growth rates and phase times of parent and hybrid cells which have been reported. Because of the complexity of these changes in the cycles of interspecific cell hybrids, we believe that somatic cell genetic analysis of the regulation of the cell cycle would be more usefully applied to intraspecific hybrids whose parents differ in only one specific cycle characteristic. 相似文献