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161.
Korf U Derdak S Tresch A Henjes F Schumacher S Schmidt C Hahn B Lehmann WD Poustka A Beissbarth T Klingmüller U 《Proteomics》2008,8(21):4603-4612
The quantitative analysis of signaling networks requires highly sensitive methods for the time-resolved determination of protein phosphorylation. For this reason, we developed a quantitative protein microarray that monitors the activation of multiple signaling pathways in parallel, and at high temporal resolution. A label-free sandwich approach was combined with near infrared detection, thus permitting the accurate quantification of low-level phosphoproteins in limited biological samples corresponding to less than 50,000 cells, and with a very low standard deviation of approximately 5%. The identification of suitable antibody pairs was facilitated by determining their accuracy and dynamic range using our customized software package Quantpro. Thus, we are providing an important tool to generate quantitative data for systems biology approaches, and to drive innovative diagnostic applications. 相似文献
162.
163.
Identification of an insulin-regulated lysophospholipase with homology to neuropathy target esterase
Kienesberger PC Lass A Preiss-Landl K Wolinski H Kohlwein SD Zimmermann R Zechner R 《The Journal of biological chemistry》2008,283(9):5908-5917
Neuropathy target esterase (NTE) is a member of the family of patatin domain-containing proteins and exhibits phospholipase activity in brain and cultured cells. NTE was originally identified as target enzyme for organophosphorus compounds that cause a delayed paralyzing syndrome with degeneration of nerve axons. Here we show that the structurally related murine protein NTE-related esterase (NRE) is a potent lysophospholipase. The enzyme efficiently hydrolyzes sn-1 esters in lysophosphatidylcholine and lysophosphatidic acid. No lipase activity was observed when triacylglycerols, cholesteryl esters, retinyl esters, phosphatidylcholine, or monoacylglycerol were used as substrates. Although NTE is predominantly expressed in the nervous system, we found the highest NRE mRNA levels in testes, skeletal muscle, cardiac muscle, and adipose tissue. Induction of NRE mRNA concentrations in these tissues during fasting suggested a nutritional regulation of enzyme expression and, in accordance with this observation, insulin reduced NRE mRNA levels in a dose-dependent manner in 3T3-L1 adipocytes. A green fluorescent protein-NRE fusion protein colocalized to the endoplasmic reticulum and lipid droplets. Thus, NRE is a previously unrecognized ER- and lipid droplet-associated lysophospholipase. Regulation of enzyme expression by the nutritional status and insulin suggests a role of NRE in the catabolism of lipid precursors and/or mediators that affect energy metabolism in mammals. 相似文献
164.
Measurement of net ecosystem exchange,productivity and respiration in three spruce forests in Sweden shows unexpectedly large soil carbon losses 总被引:3,自引:1,他引:2
Anders Lindroth Leif Klemedtsson Achim Grelle Per Weslien Ola Langvall 《Biogeochemistry》2008,89(1):43-60
Measurement of net ecosystem exchange was made using the eddy covariance method above three forests along a north-south climatic gradient in Sweden: Flakaliden in the north, Knottåsen in central and Asa in south Sweden. Data were obtained for 2 years at Flakaliden and Knottåsen and for one year at Asa. The net fluxes (Nep) were separated into their main components, total ecosystem respiration (Rt) and gross primary productivity (Pg). The maximum half-hourly net uptake during the heart of the growing season was highest in the southernmost site with ?0.787 mg CO2 m?2 s?1 followed by Knottåsen with ?0.631 mg CO2 m?2 s?1 and Flakaliden with ?0.429 mg CO2 m?2 s?1. The maximum respiration rates during the summer were highest in Knottåsen with 0.245 mg CO2 m?2 s?1 while it was similar at the two other sites with 0.183 mg CO2 m?2 s?1. The annual Nep ranged between uptake of ?304 g C m?2 year?1 (Asa) and emission of 84 g C m?2 year?1 (Knottåsen). The annual Rt and Pg ranged between 793 to 1253 g C m?2 year?1 and ?875 to ?1317 g C m?2 year?1, respectively. Biomass increment measurements in the footprint area of the towers in combination with the measured net ecosystem productivity were used to estimate the changes in soil carbon and it was found that the soils were losing on average 96–125 g C m?2 year?1. The most plausible explanation for these losses was that the studied years were much warmer than normal causing larger respiratory losses. The comparison of net primary productivity and Pg showed that ca 60% of Pg was utilized for autotrophic respiration. 相似文献
165.
Plastoquinol as a singlet oxygen scavenger in photosystem II 总被引:2,自引:0,他引:2
It has been found that in Chlamydomonas reinhardtii cells, under high-light stress, the level of reduced plastoquinone considerably increases while in the presence of pyrazolate, an inhibitor of plastoquinone and tocopherol biosynthesis, the content of reduced plastoquinone quickly decreases, similarly to alpha-tocopherol. In relation to chlorophyll, after 18 h of growth under low light with the inhibitor, the content of alpha-tocopherol was 22.2 mol/1000 mol chlorophyll and that of total plastoquinone (oxidized and reduced) was 19 mol/1000 mol chlorophyll, while after 2 h of high-light stress the corresponding amounts dropped to 6.4 and 6.2 mol/1000 mol chlorophyll for alpha-tocopherol and total plastoquinone, respectively. The degradation of both prenyllipids was partially reversed by diphenylamine, a singlet oxygen scavenger. It was concluded that plastoquinol, as well as alpha-tocopherol is decomposed under high-light stress as a result of a scavenging reaction of singlet oxygen generated in photosystem II. The levels of both alpha-tocopherol and of the reduced plastoquinone are not affected significantly in the absence of the inhibitor due to a high turnover rate of both prenyllipids, i.e., their degradation is compensated by fast biosynthesis. The calculated turnover rates under high-light conditions were twofold higher for total plastoquinone (0.23 nmol/h/ml of cell culture) than for alpha-tocopherol (0.11 nmol/h/ml). We have also found that the level of alpha-tocopherolquinone, an oxidation product of alpha-tocopherol, increases as the alpha-tocopherol is consumed. The same correlation was also observed for gamma-tocopherol and its quinone form. Moreover, in the presence of pyrazolate under low-light growth conditions, the synthesis of plastoquinone-C, a hydroxylated plastoquinone derivative, was stimulated in contrast to plastoquinone, indicating for the first time a functional role for plastoquinone-C. The presented data also suggest that the two plastoquinones may have different biosynthetic pathways in C. reinhardtii. 相似文献
166.
167.
Schlapbach A Feifel R Hawtin S Heng R Koch G Moebitz H Revesz L Scheufler C Velcicky J Waelchli R Huppertz C 《Bioorganic & medicinal chemistry letters》2008,18(23):6142-6146
Pyrrolo-pyrimidones of the general structure 1 were synthesized and evaluated for their potential as MK2 inhibitors. Potent derivatives were discovered which inhibit MK2 in the nanomolar range and show potent inhibition of cytokine release from LPS-stimulated monocytes. These derivatives were shown to inhibit phosphorylation of hsp27, a downstream target of MK2 and are modestly selective in a panel of 28 kinases. 相似文献
168.
169.
Ingeborg Teppner Sonja Becker Martin Hrabé de Angelis Achim Gossler Johannes Beckers 《BMC developmental biology》2007,7(1):68
Background
Expression of the mouse Delta-like 1 (Dll1) gene in the presomitic mesoderm and in the caudal halves of somites of the developing embryo is required for the formation of epithelial somites and for the maintenance of caudal somite identity, respectively. The rostro-caudal polarity of somites is initiated early on within the presomitic mesoderm in nascent somites. Here we have investigated the requirement of restricted Dll1 expression in caudal somite compartments for the maintenance of rostro-caudal somite polarity and the morphogenesis of the axial skeleton. We did this by overexpressing a functional copy of the Dll1 gene throughout the paraxial mesoderm, in particular in anterior somite compartments, during somitogenesis in transgenic mice. 相似文献170.
Stephanie Plog Lars Mundhenk Melanie K. Bothe Nikolai Klymiuk Achim D. Gruber 《The journal of histochemistry and cytochemistry》2010,58(9):785-797
Emerging porcine models of cystic fibrosis (CF) are expected to mimic the human disease more closely than current mouse models do. However, little is known of the tissue and cellular expression patterns of the porcine CF transmembrane conductance regulator (pCFTR) and possible differences from human CFTR (hCFTR). Here, the expression pattern of pCFTR was systematically established on the mRNA and protein levels. Using specific anti-pCFTR antibodies, the majority of the protein was immunohistochemically detected on paraffin-embedded sections and on cryostate sections in the apical cytosol of intestinal crypt epithelial cells, nasal, tracheal, and bronchial epithelial cells, and other select, mostly glandular epithelial cells. Confocal laser scanning microscopy with co-localization of the Golgi marker 58K localized the protein in the cytosol between the Golgi apparatus and the apical cell membrane with occasional punctate or diffuse staining of the apical membrane. The tissue and cellular distribution patterns were confirmed by RT-PCR from whole tissue lysates or select cells after laser capture microdissection. Thus, expression of pCFTR was found to largely resemble that of hCFTR except for the kidney, brain, and cutaneous glands, which lack expression in pigs. Species-specific differences between pCFTR and hCFTR may become relevant for future interpretations of the CF phenotype in pig models. (J Histochem Cytochem 58:785–797, 2010) 相似文献