Résumé
To study the chemical constituents of the branches of Tamarix rasissima, repeated silica gel column chromatography, Sephadex LH-20 chromatography and recrystallization were applied for chemical constituents isolation and purification. Ten phenolic compounds were isolated from the n-BuOH fraction and their structures were elucidated by physical properties and spectra analysis such as UV, ESI-MS and NMR as monodecarboxyellagic acid (1), ellagic acid (2), 3, 3'-di-O-methylellagic acid (3), 3, 3'-di-O-methylellagic acid-4-O-beta-D-glucopyranoside (4), 3, 3'-di-O-methylellagic acid-4'-O-alpha-D-arabinfuranoside (5), ferulic acid (6), isoferulic acid (7), caffeic acid (8), 4-O-acetyl-caffeic acid (9), and 4-methyl-1, 2-benzenediol (10). All compounds except for isoferulic acid were isolated firstly from this plant except for isoferulic acid, and compounds 5, 9 and 10 were obtained from Tamarix genus for the first time.
Sujets)
Médicaments issus de plantes chinoises , Chimie , Spectroscopie par résonance magnétique , Structure moléculaire , Phénols , Chimie , Spectrométrie de masse ESI , Tamaricaceae , ChimieRésumé
<p><b>OBJECTIVE</b>To study the interaction between ShcD and TrkC and to reveal the molecular mechanism of the downstream signal transduction of TrkC.</p><p><b>METHODS</b>Yeast two-hybrid assay was used. The intracellular domains of TrkC and TrkC mutants were cloned into pAS2-1, and ShcD and its four domains (CH2, PTB, CH1, and SH2 domains) were cloned into pACT2 vector respectively. The constructs were separately cotransformed into yeast. beta-galactosidase activity was measured to detect their interactions. TrkC was cloned into pmRFP (carrying red fluorescent protein), and ShcD was cloned into pEGFP (carrying green fluorescent protein). pmRFP-TrkC and pEGFP-ShcD were co-transfected into 293T cells, and then the cells were fixed and subjected to confocal analysis to study their subcellular localization.</p><p><b>RESULTS</b>ShcD interacted with TrkC but not with kinase dead mutant TrkCM1(K572A). Both PTB and SH2 domains were capable of binding to TrkC, and PTB domain bound NPQY motif of TrkC. ShcD colocalized with TrkC throughout the cytoplasm and in the plasma membrane in 293T cells.</p><p><b>CONCLUSION</b>ShcD binds to TrkC in a kinase-activity-dependent manner through its PTB and SH2 domains.</p>
Sujets)
Humains , Protéines adaptatrices de la transduction du signal , Génétique , Métabolisme , Sites de fixation , Cellules cultivées , Vecteurs génétiques , Plasmides , Génétique , Liaison aux protéines , Récepteur trkC , Génétique , Métabolisme , Protéines adaptatrices de signalisation Shc , Génétique , Métabolisme , Transfection , Transformation bactérienne , Techniques de double hybride , Domaine d'homologie SRC , GénétiqueRésumé
<p><b>OBJECTIVE</b>To study the role of adaptor protein Dok6 in neurite outgrowth in PC12 cells.</p><p><b>METHODS</b>Series of fusion clones were constructed by fusing different domains of Dok6 into mutant TrkC/Y516F. These constructs were transiently transfected into PC12 cells separately and the expression levels of fusion proteins were detected by Western blot. Neurite outgrowth in these PC12 cells was tested after stimulation of NT-3.</p><p><b>RESULTS</b>Each fusion clone was stably expressed in PC12 cells. The fusion clones that fused both TrkC/Y516F-Dok6 (PTB+C) and TrkC/Y516F-Dok6C rescued the loss of neurite outgrowth in PC12 cells resulting from the mutation in tyrosine 516, while fusion clones that fused with single TrkC/Y516F-Dok6PTB did not show such effect.</p><p><b>CONCLUSION</b>Dok6 can promote neurite outgrowth induced by NT-3 stimulation through its C-terminal in TrkC-positive PC12 cells.</p>
Sujets)
Animaux , Rats , Protéines adaptatrices de la transduction du signal , Génétique , Métabolisme , Neurites , Physiologie , Neurotrophine-3 , Pharmacologie , Cellules PC12 , Récepteur trkC , Métabolisme , TransfectionRésumé
<p><b>OBJECTIVE</b>To study the chemical constituents from Lamium maculatum L. var Kansuense.</p><p><b>METHOD</b>The chemical constituents were isolated and repeatedly purified by silica gel column chromatography and the structures were elucidated by the NMR spectra and physico-chemical properties.</p><p><b>RESULT</b>Ten compounds were obtained and they were identified as D-mannitol, beta-sitosterol, stigmasterol, rutin, 3'-methylquercetin-3-O-rutinoside, n-butyl-beta-D-fructopyranoside, daucosterol, acteoside, 20-hydroxyecdysone, allantoin.</p><p><b>CONCLUSION</b>All the compounds were obtained from L. maculatum L. var Kansuense for the first time.</p>
Sujets)
Allantoïne , Chimie , Ecdystérone , Chimie , Glucosides , Chimie , Lamiaceae , Chimie , Mannitol , Chimie , Phénols , Chimie , Plantes médicinales , Chimie , Rutoside , Chimie , Sitostérol , Chimie , Stigmastérol , ChimieRésumé
Protein fulfilling the their roles, one of important ways is through protein-protein interaction. In functional genomic era, identifying all of protein-protein interaction in proteome and mapping the protein interactions that have been attracting many scientists' attention , of which large-scale yeast two-hybrid system is one strategy of most widely used. In recent two years, ambitious projects have launched to examine all of the protein-protein interaction in Saccharomyces cer-evisiae using large-scale yeast two-hybrid system. Nevertheless, huge protein network is larger than that we predict and single yeast two-hybrid system cannot solve all the problems, which need be complemented by other wags.