Search results for "EXPRESSION"
showing 10 items of 5168 documents
Construction and expression of a dual vector for chemo-enzymatic synthesis of plant indole alkaloids inEscherichia coli
2010
A dual vector (pQE-70-STR1-SG) containing coding regions of strictosidine synthase (STR1, EC 4.3.3.2) and strictosidine glucosidase (SG, EC 3.2.1.105) from the Indian medicinal plant Rauvolfia serpentina was constructed. Functional expression of the vector in Escherichia coli cells (M15 strain) was proven by isolation of prepurified enzyme extracts, which show both STR1 and SG activities. Incubation of the enzyme in the presence of tryptamine and secologanin delivered the indole alkaloid cathenamine, demonstrating functional co-expression of both STR1- and SG-cDNAs. Cathenamine reduction by sodium borohydride leading to tetrahydroalstonine revealed the chemo-enzymatic indole alkaloid synthe…
Crystallization and preliminary X-ray analysis of strictosidine synthase and its complex with the substrate tryptamine
2005
Strictosidine synthase (STR1) is a central enzyme that participates in the biosynthesis of almost all plant monoterpenoid indole alkaloids. After heterologous expression in Escherichia coli, crystals of STR1 and its substrate complex with tryptamine were obtained by the hanging-drop technique at 302–304 K with potassium sodium tartrate tetrahydrate as precipitant. All crystals belong to space group R3. The native STR1 crystals diffract to 2.95 Å and have unit-cell parameters a = b = 150.3, c = 122.4 Å. The tryptamine complex crystals diffract to 2.38 Å, with unit-cell parameters a = b = 147.3, c = 122.3 Å.
A helicopter perspective on TB biomarkers: pathway and process based analysis of gene expression data provides new insight into TB pathogenesis.
2013
Biomarker host genetic signatures are considered key tools for improved early diagnosis of tuberculosis (TB) disease (development). The analysis of gene expression changes based on a limited number of genes or single study designs, however, may not be sufficient for the identification of universal diagnostic biomarker profiles. Here we propose that biological pathway and process based analyses from multiple data sets may be more relevant for identification of key pathways in TB pathogenesis, and may reveal novel candidate diagnostic TB biomarkers. A number of independent genome-wide gene expression studies have recently been performed to study expression of biomarkers for TB disease. We hav…
A FOX Binding Site is Necessary for the Activation of Pl-Tuba1a Gene in the neurogenic domains
2016
All echinoderm larvae possess a nervous system consisting of a ciliary band and associated sensory ganglia (apical, oral and lateral ganglia) that controls swimming and feeding. Neurons of the larval nervous system first appear as neuroblasts in the thickened ectoderm of the animal plate (anterior neuroectoderm, ANE) at the late blastula – early gastrula stage and then also in the ciliary band. The neural differentiation process of sea urchin embryos has been analysed and the Gene Regulatory Network involved in the differentiation processes is extensively studied. We have previously isolated an alpha tubulin family member of the sea urchin Paracentrotus lividus (Pl-Tuba1a, formerly known as…
MMP-10/stromelysin-2 promotes invasion of head and neck cancer.
2011
BackgroundPeriostin, IFN-induced transmembrane protein 1 (IFITM1) and Wingless-type MMTV integration site family, member 5B (Wnt-5b) were previously identified as the invasion promoted genes of head and neck squamous cell carcinoma (HNSCC) by comparing the gene expression profiles between parent and a highly invasive clone. We have previously reported that Periostin and IFITM1 promoted the invasion of HNSCC cells. Here we demonstrated that Wnt-5b overexpression promoted the invasion of HNSCC cells. Moreover, stromelysin-2 (matrix metalloproteinase-10; MMP-10) was identified as a common up-regulated gene among Periostin, IFITM1 and Wnt-5b overexpressing HNSCC cells by using microarray data s…
CCL3 and CCL4, the Major Chemokines Produced by CD38+ Chronic Lymphocytic Leukemia Cells, Facilitate Microenvironmental Interactions of Neoplastic Ce…
2008
Abstract CD38, a negative prognostic marker for patients with CLL, has been demonstrated to be a key molecule in the interactions occurring in the context of tumor microenvironment, mediating both survival and migratory signals for CLL cells. By taking advantage of gene expression profiling studies (GEP) comparing 11 CD38pos (CD38>30%) and 15 CD38neg (CD38<10%) CLLs, we identified as over-expressed in CD38pos CLL cells: i) genes for the two C-C chemokines CCL3 and CCL4 (median-log difference, MLD-CCL3= 3.5; MLD-CCL4=4.4); real-time quantitative PCR (RTQ-PCR) of selected cases confirmed GEP results; ii) the gene for CD49d (MLD=4.4); a high correlation between CD38 and CD49d pro…
Analysis of p53 and mdm2 proteins in malignant fibrous histiocytoma in absence of gene alteration: prognostic significance.
2000
TP53 and MDM2 genes and their protein expression were evaluated in frozen and paraffin-embedded tissue from 27 patients with malignant fibrous histiocytoma to elucidate the relationship between them, their implication in tumor progression mechanisms and their possible diagnostic-prognostic value in malignant fibrous histiocytoma. Single-strand conformation polymorphism analysis and direct sequencing of polymerase chain reaction-amplified DNA were used to establish two TP53 mutations (7.4%): a point mutation and a 63-bp duplication. Amplification of the MDM2 gene was observed in two tumors (7.4%) by means of Southern-blot analysis, one of them also carrying the TP53 point mutation. Immunohis…
Analysis of the p53 and MDM-2 gene in acute myeloid leukemia
1996
The MDM-2 (murine double minute 2) gene codes for a cellular protein that can bind to the p53 tumor suppressor gene product, thereby functioning as a negative regulator of p53. In order to define the role of the MDM-2 gene in the pathogenesis of human acute myeloid leukemia, the expression and the sequence of the MDM-2 gene were examined in samples of bone marrow and/or peripheral mononuclear cells of 38 patients by using immunostaining, polymerase chain reaction (PCR), single strand conformation polymorphism, and sequencing. Immunohistochemical staining detected a weak accumulation of the MDM-2 protein in AML patients of FAB classification M4 and M5. RT-PCR analysis revealed a heterogeneou…
Direct Activation of Bax by p53 Mediates Mitochondrial Membrane Permeabilization and Apoptosis
2004
The tumor suppressor p53 exerts its anti-neoplastic activity primarily through the induction of apoptosis. We found that cytosolic localization of endogenous wild-type or trans-activation–deficient p53 was necessary and sufficient for apoptosis. p53 directly activated the proapoptotic Bcl-2protein Bax in the absence of other proteins to permeabilize mitochondria and engage the apoptotic program. p53 also released both proapoptotic multidomain proteins and BH3-only proteins [Proapoptotic Bcl-2family proteins that share only the third Bcl-2homology domain (BH3)] that were sequestered by Bcl-xL. The transcription-independent activation of Bax by p53 occurred with similar kinetics and concentra…
Progression of colorectal cancers correlates with overexpression and loss of polarization of expression of the htid-1 tumor suppressor.
2007
Recently, we identified htid-1, the human counterpart of the Drosophila tumor suppressor gene lethal(2)tumorous imaginal discs [l(2)tid], as a direct molecular ligand of the adenomatous polyposis coli (APC) tumor suppressor. The gene encodes three cytosolic (Tid50, Tid48 and Tid46) and three mitochondrial (Tid43, Tid40 and Tid38) proteins. In the colorectal epithelium the cytosolic forms hTid50/hTid48 interact under physiological conditions with the N-terminal region of APC. This complex which associates with additional proteins such as Hsp70, Hsc70, Actin, Dvl and Axin defines a novel physiological state of APC unrelated to beta-catenin degradation. Here we show that the expression of the …