Quorum sensing is a regulatory system used by bacteria for controlling gene expression in response to increasing cell density.{15370} This regulatory process manifests itself with a variety of phenotypes including biofilm formation and virulence factor production.{13434} Coordinated gene expression is achieved by the production, release, and detection of small diffusible signal molecules called autoinducers. The N-acylated homoserine lactones (AHLs) comprise one such class of autoinducers, each of which generally consists of a fatty acid coupled with homoserine lactone (HSL). Regulation of bacterial quorum sensing signaling systems to inhibit pathogenesis represents a new approach to antimicrobial therapy in the treatment of infectious diseases.{15369} AHLs vary in acyl group length (C4-C18), in the substitution of C3 (hydrogen, hydroxyl, or oxo group), and in the presence or absence of one or more carbon-carbon double bonds in the fatty acid chain. These differences confer signal specificity through the affinity of transcriptional regulators of the LuxR family.{15398} In one of the most-studied quorum-sensing systems in gram-negative bacteria, the LuxI AHL synthase catalyzes the production of N-(β-ketocaproyl)-L-homoserine lactone utilizing S-adenosylmethionine and hexanoyl-acyl carrier protein as reaction substrates in the marine bioluminescence bacterium V. fischeri.{16881} At increased populations of the bacteria, localized higher concentrations of 3-O-C6-HSL, an endogenous ligand to transcriptional factor LuxR, leads to increased production of both the AHL synthase and proteins responsible for bioluminescence.{15370} Numerous other species of bacteria also employ N-(β-ketocaproyl)-L-homoserine lactone in cell-to-cell communication.{16800,15932,16767,15399}
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A HSL compound produced in the marine bioluminescence bacterium V. fischeri
Formal name: 3-oxo-N-[(3S)-tetrahydro-2-oxo-3-furanyl]-hexanamide
Synonyms: 3-O-C6-(L)-HSL
Molecular weight: 213.2
CAS: 143537-62-6
Purity: ≥95%
Formulation: A crystalline solid
Product Type|Biochemicals|Homoserine Lactones||Research Area|Immunology & Inflammation||Research Area|Infectious Disease|Bacterial Diseases||Research Area|Infectious Disease|Quorum Sensing
The PtdIn phosphates play an important role in the generation and transduction of intracellular signals.{8344,4096,14518} PtdIns-(3,4,5)-P3-biotin is an affinity probe which allows the PIP3 to be detected through an interaction with the biotin ligand. This design allows PtdIns-(3,4,5)-P3-biotin to serve as a general probe for any protein with a high affinity binding interaction with inositol-(3,4,5)-triphosphate phospholipids, such as phosphatidylinositol 3-kinase, PTEN, or PH-domain-containing proteins.
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The tetracycline repressor (TetR) is a transcriptional regulator which normally binds tightly to its palindromic tetO operator DNA, blocking gene expression.{17508} Tet causes the repressor to dissociate from the DNA, allowing transcription to occur. A novel reverse TetR (revTetR) requires tetracycline as a co-repressor to bind tetO and block transcription.{17509,17510} Anhydrotetracycline (hydrochloride) is a powerful effector in both the tetracycline repressor (TetR) and reverse TetR (revTetR) systems, binding the Tet repressor 35-fold more strongly than Tet.{17508,17511} Moreover, anhydrotetracycline poorly binds the 30S ribosomal subunit, compared to Tet,{17512} so it does not act as a general inhibitor of translation and is a poor antibiotic. Perhaps related to this, the concentration of anhydrotetracycline that inhibits eukaryotic cell growth is more than a 1,000-fold above the dose that alters transcription through TetR.{17508}
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The nuclear factor-κB (NF-κB) regulates the expression of numerous genes involved in immunity and inflammation, cellular stress responses, growth, and apoptosis. Resveratrol, a polyphenolic trans-stilbene, is a known inhibitor of the activation of NF-κB and exhibits activity against a wide variety of cancer cells. CAY10512 is a substituted trans-stilbene analog of resveratrol that is 100-fold more potent as measured by antioxidant activity. The IC50 value for inhibition of TNFα-induced activation of NF-κB by CAY10512 is 0.15 µM compared to 20 µM by resveratrol.{14545}
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1,2-Dipalmitoyl-sn-glycero-3-PC (DPPC) is a zwitterionic glycerophospholipid commonly used in the formation of lipid monolayers, bilayers, and liposomes for use in a variety of applications.{14480,24261,14478,14479} It has been used in the formation of proteoliposomes for implantation of γ-glutamyl transpeptidase into human erythrocyte membranes.{14478} Incorporation of glycosphingolipid antigens into DPPC-containing liposomes increases the immunogenicity of the antigens in mice.{14479}
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