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排序方式: 共有460条查询结果,搜索用时 15 毫秒
91.
Rafal Bartoszewski Jaroslaw Króliczewski Arkadiusz Piotrowski Anna Janaszak Jasiecka Sylwia Bartoszewska Briana Vecchio-Pagan Lianwu Fu Aleksandra Sobolewska Sadis Matalon Garry R. Cutting Steven M. Rowe James F. Collawn 《Cellular & molecular biology letters》2016,21(1):23
Synonymous or silent mutations are often overlooked in genetic analyses for disease-causing mutations unless they are directly associated with potential splicing defects. More recent studies, however, indicate that some synonymous single polynucleotide polymorphisms (sSNPs) are associated with changes in protein expression, and in some cases, protein folding and function. The impact of codon usage and mRNA structural changes on protein translation rates and how they can affect protein structure and function is just beginning to be appreciated. Examples are given here that demonstrate how synonymous mutations alter the translational kinetics and protein folding and/or function. The mechanism for how this occurs is based on a model in which codon usage modulates the translational rate by introducing pauses caused by nonoptimal or rare codons or by introducing changes in the mRNA structure, and this in turn influences co-translational folding. Two examples of this include the multidrug resistance protein (p-glycoprotein) and the cystic fibrosis transmembrane conductance regulator gene (CFTR). CFTR is also used here as a model to illustrate how synonymous mutations can be examined using in silico predictive methods to identify which sSNPs have the potential to change protein structure. The methodology described here can be used to help identify “non-silent” synonymous mutations in other genes. 相似文献
92.
Metallothioneins 1 and 2, but not 3, are regulated by nutritional status in rat white adipose tissue
Sylwia Szrok Ewa Stelmanska Jacek Turyn Aleksandra Bielicka-Gieldon Tomasz Sledzinski Julian Swierczynski 《Genes & nutrition》2016,11(1):18
Background
Cumulating evidence underlines the role of adipose tissue metallothionein (MT) in the development of obesity and type 2 diabetes. Fasting/refeeding was shown to affect MT gene expression in the rodent liver. The influence of nutritional status on MT gene expression in white adipose tissue (WAT) is inconclusive. The aim of this study was to verify if fasting and fasting/refeeding may influence expression of MT genes in WAT of rats.Results
Fasting resulted in a significant increase in MT1 and MT2 gene expressions in retroperitoneal, epididymal, and inguinal WAT of rats, and this effect was reversed by refeeding. Altered expressions of MT1 and MT2 genes in all main fat depots were reflected by changes in serum MT1 and MT2 levels. MT1 and MT2 messenger RNA (mRNA) levels in WAT correlated inversely with serum insulin concentration. Changes in MT1 and MT2 mRNA levels were apparently not related to total zinc concentrations and MTF1 and Zn transporter mRNA levels in WAT. Fasting or fasting/refeeding exerted no effect on the expression of MT3 gene in WAT. Addition of insulin to isolated adipocytes resulted in a significant decrease in MT1 and MT2 gene expressions. In contrast, forskolin or dibutyryl-cAMP (dB-cAMP) enhanced the expressions of MT1 and MT2 genes in isolated adipocytes. Insulin partially reversed the effect of dB-cAMP on MT1 and MT2 gene expressions.Conclusions
This study showed that the expressions of MT1 and MT2 genes in WAT are regulated by nutritional status, and the regulation may be independent of total zinc concentration.93.
94.
Buszewski B Kowalska S Kowalkowski T Rozpedowska K Michel M Jonsson T 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,845(2):253-260
In recent years, multivariate techniques have been utilized to evaluate reversed-phase high-performance liquid chromatographic data. In the present study, 11 high-performance liquid chromatography (HPLC) columns were divided into several groups according to the retention factors of 12 peptides. Principal component analysis (PCA) and cluster analysis (CA) were used in column and peptides' comparison and grouping. CA results indicated that all stationary phases may be generally grouped into several clusters, due to stationary phase structure and properties. On the other hand, interesting results were obtained with the use of PC. There is almost linear relationship between classified HPLC columns in the space of new PCs, which is connected with meaning of the PC's reflected in their loading values. The first component describes non-polar properties of peptides, whereas the second component is loaded with polar peptides having much lower logP values. PCA and CA were also used in peptides comparison however, complete explanation of peptides grouping still remains unclear. 相似文献
95.
96.
S Goraj M Libik-Konieczny E Surówka P Rozpądek A Kalisz A Libik M Nosek P Waligórski Z Miszalski 《Journal of plant physiology》2012,169(12):1158-1164
Differences in the activity of superoxide dismutase, catalase (CAT) and ascorbate peroxidase (APX) as well as in the concentration of ascorbate, tocopherol and hydrogen peroxide (H?O?) were found in leaves from different layers of the Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) head. The youngest chlorophyll-deficient leaves from the most inner layers of the cabbage head were characterized by a high concentration of ascorbate, high activity of iron superoxide dismutase (FeSOD), cooper/zinc superoxide dismutase (Cu/ZnSOD) and a low content of H?O?. On the other hand, activity of CAT, manganese superoxide dismutase (MnSOD) and APX and tocopherol content were highest in chlorophyll-rich leaves from outer parts. The results of this work are interesting from the human nutrition standpoint, as the measured antioxidants have beneficial effects on human health. They can also be utilized to improve storage conditions due to an unequivocal function of antioxidant molecules in maintaining postharvest quality of vegetables. 相似文献
97.
Distinct DNA repair pathways involving RecA and nonhomologous end joining in Mycobacterium smegmatis
Korycka-Machala M Brzostek A Rozalska S Rumijowska-Galewicz A Dziedzic R Bowater R Dziadek J 《FEMS microbiology letters》2006,258(1):83-91
Mycobacterium smegmatis was used to study the relationship between DNA repair processes involving RecA and nonhomologous end joining (NHEJ). The effect of gene deletions in recA and/or in two genes involved in NHEJ (ku and ligD) was tested on the ability of bacteria to join breaks in plasmids transformed into them and in their response to chemicals that damage DNA. The results provide in vivo evidence that only NHEJ is required for the repair of noncompatible DNA ends. By contrast, the response of mycobacteria to mitomycin C preferentially involved a RecA-dependent pathway. 相似文献
98.
Oczko-Wojciechowska M Włoch J Wiench M Fujarewicz K Simek K Gala G Gubała E Szpak-Ulczok S Jarzab B 《Endokrynologia Polska》2006,57(4):420-426
INTRODUCTION: Medullary thyroid carcinoma occurs both as a sporadic and a familial disease. Inherited MTC (iMTC) patients usually exhibit better prognosis than patients with sporadic form of MTC (sMTC), however, in both subtypes the outcome is unpredictable. No molecular markers contributing to the prognosis or predicting the type of therapy have been introduced to clinical practice until now. The aim of this study was to analyze gene expression pattern of MTC by high density oligonucleotide microarray. MATERIAL AND METHODS: 24 samples were studied: 12 MTC and 12 corresponding normal tissues, (Affymetrix HG-U 133A). Among MTC patients there were half inherited cases and half sporadic ones. RESULTS: First, the differences between MTC and thyroid tissue were analyzed by Singular Value Decomposition (SVD) which indicated three main modes determining the variability of gene expression profile: the first two were related to the tumor/normal tissue difference and the third one was related to the immune response. The characteristic expression pattern, beside of numerous changes within cancer- related genes, included many up-regulated genes specific for thyroid C cells. Further analysis of the second component revealed two subgroups of MTC, but the subdivision was not related to the iMTC/sMTC difference. Recursive Feature Replacement (RFR) confirmed the very similar expression profile in both forms of MTC. With subsequent ANOVA analysis some genes with differential expression could be specified, among them monoamine oxidase B (MAOB) and gamma-aminobutyric acid receptor (GABRR1) which were consistently up-regulated in sMTC. In contrary, some genes involved in regulation of cell proliferation: opioid growth factor receptor(OGFR) and synaptotagmin V (SYT 5) were up-regulated in iMTC. CONCLUSIONS: The obtained data indicate a very similar gene expression pattern in inherited and sporadic MTC. Minor differences in their molecular profile require further analysis. 相似文献
99.
Mitochondria: more than just a powerhouse 总被引:26,自引:0,他引:26
Pioneering biochemical studies have long forged the concept that the mitochondria are the 'energy powerhouse of the cell'. These studies, combined with the unique evolutionary origin of the mitochondria, led the way to decades of research focusing on the organelle as an essential, yet independent, functional component of the cell. Recently, however, our conceptual view of this isolated organelle has been profoundly altered with the discovery that mitochondria function within an integrated reticulum that is continually remodeled by both fusion and fission events. The identification of a number of proteins that regulate these activities is beginning to provide mechanistic details of mitochondrial membrane remodeling. However, the broader question remains regarding the underlying purpose of mitochondrial dynamics and the translation of these morphological transitions into altered functional output. One hypothesis has been that mitochondrial respiration and metabolism may be spatially and temporally regulated by the architecture and positioning of the organelle. Recent evidence supports and expands this idea by demonstrating that mitochondria are an integral part of multiple cell signaling cascades. Interestingly, proteins such as GTPases, kinases and phosphatases are involved in bi-directional communication between the mitochondrial reticulum and the rest of the cell. These proteins link mitochondrial function and dynamics to the regulation of metabolism, cell-cycle control, development, antiviral responses and cell death. In this review we will highlight the emerging evidence that provides molecular definition to mitochondria as a central platform in the execution of diverse cellular events. 相似文献
100.