Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The generation of 13C-labelled lactate by colon carcinoma cells of the Caco-2 line incubated for 120 min in the presence of [2-13C]propionate (10 mM) was assessed by 13C NMR. About 10% of the total amount of 13C-labelled lactate was recovered in the cell pellet and displayed a [2-13C]lactate/[3-13C]lactate isotopomer ratio of 1.18 +/- 0.01. An even higher isotopomer ratio of 1.53 +/- 0.14 was observed in the case of 13C-labelled lactate released by the cells into the incubation medium. These findings indicate that, in the Caco-2 cells, metabolic intermediates of the Krebs cycle undergo enzyme-to-enzyme channelling in the sequence of reactions catalysed by succinyl-CoA synthetase, succinate dehydrogenase and fumarase.
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PMID:Enzyme-to-enzyme channelling of Krebs cycle metabolic intermediates in Caco-2 cells exposed to [2-13c]propionate. 876 Mar 74

The dimethyl esters of succinic acid (SAD) and glutamic acid (GME) were found to be efficiently metabolized in colon carcinoma cells of the Caco-2 line. The rate of [1,4-14C]SAD and [2,3-14C]SAD conversion to radioactive acidic metabolites, CO2, amino acids, pyruvic acid, and lactic acid suggested that the catabolism of the ester-derived succinic acid occurred mainly through the sequence of reactions catalyzed by succinate dehydrogenase, fumarase, and the malic enzyme. This coincided with a marked sparing action of SAD on the utilization of D-[2-(3)H]glucose and D-[5-(3)H]glucose and generation of 14C-labeled acid metabolites, CO2, and lactic acid from D-[U-14C]glucose by the enterocytes. Likewise, the conversion of [U-14C]GME to 14C-labeled amino acids, its oxidation compared with that of [1-(14)C]GME, and the production of NH4+ in the absence or presence of GME indicated efficient catabolism of the latter ester. Like SAD, GME decreased the utilization of D-[5-(3)H]glucose and generation of 14C-labeled acidic metabolites, pyruvate, and CO2 from D-[6-(14)C]glucose, while increasing the generation of 14C-labeled amino acids from the labeled hexose. The oxidation of D-[6-(14)C]glucose was even more severely inhibited by GME. In normal rat intestinal cells, SAM, SAD, and GME also exerted a marked sparing action on D-[U-14C]glucose oxidation. The present findings suggest, therefore, that these esters could possibly be used to sustain ATP generation in intestinal cells.
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PMID:Nutritional efficiency of succinic acid and glutamic acid dimethyl esters in colon carcinoma cells. 896 98

Catenins are cytoplasmic proteins that were initially identified in a complex with cadherins, a superfamily of transmembrane glycoproteins important for cell adhesion in normal and disease states. We have used gel filtration to identify four complexes of catenins in extracts from normal and transformed epithelial cells. In normal Madin-Darby canine kidney epithelial cells, a significant fraction of alpha- and beta-catenin and plakoglobin co-elute with cadherin in a high molecular weight complex (complex I). A portion of alpha-catenin and the remainder of beta-catenin and plakoglobin co-elute in a high molecular weight complex that does not contain cadherin (complex II). The remainder of alpha-catenin elutes in a low molecular weight fraction (complex III). In extracts from two colon carcinoma cell lines, HCT116 and SW480, beta-catenin elutes in an additional low molecular weight pool (complex IV) not present in Madin-Darby canine kidney cell extracts. In two subclones derived from SW480 cells, SW-E8 and SW-R2, beta-catenin is distributed evenly between high and low molecular weight pools in SW-E8 cells, whereas it elutes primarily in the low molecular weight pool (complex IV) in SW-R2 cells. These changes in beta-catenin elution profiles correlate with an increase in transformed phenotype and decreased cell-cell adhesion in the SW-R2 cells.
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PMID:Identification of four distinct pools of catenins in mammalian cells and transformation-dependent changes in catenin distributions among these pools. 936 32

When epithelial cells reach confluency in vitro, a number of energy-requiring activities such as growth and motility are contact-inhibited. We investigated the possible role of the E-cadherin/catenin complex, which acts as an invasion suppressor, in contact inhibition. Three strategies for modulation of the complex were used. Firstly, the cell-cell adhesion and signal transduction functions of E-cadherin were neutralized immunologically in human MCF-7/6 mammary carcinoma cells possessing a complete complex. Secondly, the effect of E-cadherin transfection in E-cadherin negative cell lines was investigated. Thirdly, alpha-catenin deficient variants of the human HCT-8/S11 colon carcinoma cell line were compared with their parent cells. In confluent cultures functional downregulation of the E-cadherin/catenin complex did not alter cell growth nor saturation density. This was shown by cell number counts, protein staining assays, cell cycle analysis, proliferation markers (Ki67 and Proliferating Cell Nuclear Antigen) and apoptosis assays. However, confluent cells with a functionally deficient complex showed positional instability and enhanced succinate dehydrogenase-mediated mitochondrial 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl) tetrazolium bromide (MTT) conversion, as compared to cells with an active complex. Our data indicate that contact inhibition of motility and of mitochondrial enzyme activity, but not of growth is regulated by the E-cadherin/catenin complex in epithelial cells.
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PMID:Functional downregulation of the E-cadherin/catenin complex leads to loss of contact inhibition of motility and of mitochondrial activity, but not of growth in confluent epithelial cell cultures. 943 30