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Expression Products (expression + products)
Selected AbstractsIdentification of soluble CD14 as an endogenous agonist for Toll-like receptor 2 on human astrocytes by genome-scale functional screening of glial cell derived proteinsGLIA, Issue 5 2007Malika Bsibsi Abstract Human astrocytes express a limited repertoire of Toll-like receptor (TLR) family members including TLR1-4, which are expressed on the cell surface. Also, TLR3 but not TLR4 activation on astrocytes induces expression of several factors involved in neuroprotection and down-regulation of inflammation rather than in the onset of traditional pro-inflammatory reactions. The notion that astrocyte TLR may thus play a role not only in host defense but also in tissue repair responses prompted us to examine the possibility that endogenous TLR agonists could be expressed in the human central nervous system to regulate the apparently dual astrocyte functions during trauma or inflammation. As a potential source of endogenous agonists, a cDNA library derived from several human brain tumor cell lines was used. Gene pools of this library were transfected into COS-7 cells and the expression products were screened for their ability to induce TLR activation in human primary astrocytes. The screening resulted in the identification of soluble CD14. By using a panel of TLR-transfected HEK293 cells, we found that signaling by soluble CD14 was TLR2 dependent. Moreover, the CD14-triggered TLR2-mediated response in astrocytes lead to the production of CXCL8, IL-6, and IL12p40, whereas typical TLR-induced pro-inflammatory cytokines, like TNF-, and IL-1,, were not produced at detectable levels. In conclusion, our data indicate that apart from its well-known ability to act as a co-receptor for TLR-dependent signaling by peptidoglycans or LPS, soluble CD14 can also act as a direct agonist for TLR2. © 2007 Wiley-Liss, Inc. [source] EXPRESSION OF A BEE-VENOM PHOSPHOLIPASE A2 FROM APIS CERANA CERANA IN ESCHERICHIA COLIINSECT SCIENCE, Issue 1 2004Li-rong Shen Abstract, The venomous phospholipase A2 (AcPLA2) coding reading region of the Chinese honeybee (Apis cerana cerana), which is composed of 405 bp encoding a mature glycosylated peptide with 134 amino residues was transformed into the expression vector pETblue-1. Then the recombinant vector was introduced into Escherichia coli Tuner (DE3) plac I for expression. Analysis result of SDS-PAGE showed that the expression products had a protein band of about 15kD. Detection of western blot using ant-European honeybee (Apis mellifera) phospholipase A2 (AmPLA2) polyclonal serum as the first antibody showed that the expression products appeared a special blot same as the native AmPLA2. The result demonstrated that the AcPLA2 peptide had been expressed in E. coli and the AcPLA2 has the similar antigenicity as the AmPLA2. [source] Novel identification of expressed genes and functional classification of hypothetical proteins from Neisseria meningitidis serogroup APROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 18 2007Giulia Bernardini Abstract To implement the 2-DE database of serogroup A Neisseria meningitidis (MenA) and improve its potential of investigation in bacterial biology, cell extracts were separated by tricine-SDS-PAGE and 131 novel proteins were identified by ,LC-ESI-IT-MS/MS. These identifications extended to 404, the number of MenA gene expression products characterized at the proteome level, approximately covering 20% of the total ORFs predicted from genome sequence. This technical approach was particularly useful in ascertaining expression of ribosomal as well as hypothetical proteins. Particular attention was paid to functional characterization of hypothetical proteins by means of software analyses and database searches. [source] A study of Streptococcus thermophilus proteome by integrated analytical procedures and differential expression investigationsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 1 2006Simona Arena Abstract Streptococcus thermophilus is a Gram-positive bacterium belonging to the group of lactic acid bacteria, among which several genera play an essential role in manufacture of food products. Recently, a genomic consortium sequenced and annotated its entire genome, which has been demonstrated to contain 1900 coding sequences. In this study, we have revealed the expression products of almost 200 different genes using a proteomic strategy combining 2-DE plus MALDI-TOF PMF and differential 1-DE plus ,LC-ESI-IT-MS/MS. Thus, a number of cellular pathways related to important physiological processes were described at the proteomic level. Almost 50 genes were related to multiple electrophoretic species, whose heterogeneity was mainly due to variability in pI values. A 2-DE reference map obtained for lactose-grown cells was compared with those obtained after heat, cold, acid, oxidative and starvation stresses. Protein up/down-regulation measurements demonstrated that adaptation to different environmental challenges may involve the contribution of unique as well as combined physiological mechanisms. Common regulatory sites in the promoter region of genes whose expression was induced after stress were identified. These results provide a better comprehension of biochemical processes related to stress resistance in S. thermophilus, allowing defining the molecular bases of adaptative responses or markers for the identification of strains with potential industrial applications. [source] Proteomics in rheumatology: The beginning of a fairy tale?PROTEOMICS - CLINICAL APPLICATIONS, Issue 3 2008Stijn Lambrecht Abstract One of the major challenges in proteome research is to translate its applications to the setting of human diseases. Proteomics in rheumatology is an area with marked potential including applications ranging from diagnostics, over therapeutic monitoring to discovery of new potential therapeutic targets. Biomarkers will be essential to discriminate between clinical similar rheumatic diseases, to monitor disease-states or to install the best appropriate therapy. Especially in the field of rheumatology, analysis of specific genes and/or their expression products by pharmacogenetics/-genomics or pharmacoproteomics could be necessary to enable an effective, patient-tailored therapy. In rheumatology, direct examination of proteins may be of utmost importance, as it is already known that PTMs, such as citrullination of proteins or peptides, may be involved in certain rheumatic diseases. The discovery and validation of antibodies directed against citrullinated proteins/peptides in rheumatic diseases using proteome analysis approaches has been described. Gel-free methods, SELDI-approaches and classic 2-DE approaches have been deployed on body fluids as well as on target tissues in different rheumatic diseases. Proteomics in rheumatology is on the rise and pilot studies have indicated that the application of proteomics-based technologies in rheumatic diseases appears to be an exciting example of translational research. [source] Heterologous expression and characterization of recombinant glycerol dehydratase from Klebsiella pneumoniae in Escherichia coliBIOTECHNOLOGY JOURNAL, Issue 6 2007Fenghuan Wang Abstract Glycerol dehydratase (EC 4.2.1.30), as one of the key enzymes in converting glycerol to the valuable intermediate 1,3-propanediol, is important for biochemical industry. The dhaB genes encoding coenzyme B12 -dependent glycerol dehydratase in Klebsiella pneumoniae were cloned and expressed in Escherichia coli. An effective co-expression system of multiple subunits protein was constructed. Heterologous expression vectors were constructed using the splicing by overlap extension-PCR technique to co-express the three subunits of the glycerol dehydratase. After induction by isopropyl-,- D -thiogalactopyranoside, SDS-PAGE analysis revealed that: (i) only the , subunit of glycerol dehydratase was expressed in direct expression system, (ii) the three subunits of glycerol dehydratase with predicted molecular massess of 64 (agr;), 22 (,), and 16 kDa (,) were expressed simultaneously in co-expression system, and (iii) the fusion expression system expressed the fusion protein of 99 kDa. Enzyme assay showed that the activities of three heterologous expression products were 27.4, 2.3, and 0.2 U/mg. The highest enzyme activity was almost 17 times of that in K. pneumoniae. The recombinant enzyme was purified and biochemically characterized. The apparent Km values of the enzyme for coenzyme B12 and 1, 2-propanediol were 8.5 nM and 1.2 mM, respectively. The enzyme showed maximum activity at pH 8.5 and 37°C. [source] | ||||||||||