Disease relevance of chalcone

• However, the rppA gene from the Gram-positive, soil-living filamentous bacterium Streptomyces griseus encodes a 372-amino-acid protein that shows significant similarity to chalcone synthases [1].
• Chalcone isomerase (CHI) catalyzes the intramolecular cyclization of chalcone synthesized by chalcone synthase (CHS) into (2S)-naringenin, an essential compound in the biosynthesis of anthocyanin pigments, inducers of Rhizobium nodulation genes, and antimicrobial phytoalexins [2].
• The cDNA clone was identified on the basis of N-terminal sequence identity to purified S-adenosyl-L-methionine:isoliquiritigenin 2'-O-methyltransferase (chalcone OMT) and expression of enzymatically active chalcone OMT protein in Escherichia coli [3].
• Xanthohumol, the main prenylated chalcone in hops, was investigated for its antiinvasive activity on human breast cancer cell lines (MCF-7 and T47-D) in vitro [4].
• Direct and specific inactivation of rhinovirus by chalcone Ro 09-0410 [5].

High impact information on chalcone

• Transgenic Petunia plants with a chsA coding sequence under the control of a 35S promoter sometimes lose endogene and transgene chalcone synthase activity and purple flower pigment through posttranscriptional chsA RNA degradation [6].
• Ppr also regulates chalcone synthase gene expression in response to blue light with autophosphorylation inhibited in vitro by blue light [7].
• The duplicated chalcone synthase genes C2 and Whp (white pollen) of Zea mays are independently regulated; evidence for translational control of Whp expression by the anthocyanin intensifying gene in [8].
• Cloning of the two chalcone flavanone isomerase genes from Petunia hybrida: coordinate, light-regulated and differential expression of flavonoid genes [9].
• In heterozygotes, niv-525 acts in trans to reduce the steady-state level of nivea transcript produced by its Niv+ homologue and hence the quantity of chalcone synthase protein [10].

Chemical compound and disease context of chalcone

• Heterologous expression in Escherichia coli showed that PStrCHS1 performed the typical CHS reaction, that it used starter CoA-esters from the phenylpropanoid pathway, and that it performed three condensation reactions with malonyl-CoA, followed by the ring closure to the chalcone [11].
• Induction of apoptosis and cell cycle arrest by a chalcone panduratin A isolated from Kaempferia pandurata in androgen-independent human prostate cancer cells PC3 and DU145 [12].
• Grapevine stilbene synthase cDNA only slightly differing from chalcone synthase cDNA is expressed in Escherichia coli into a catalytically active enzyme [13].
• The heterologous enzyme in the crude E. coli extract exhibit high acridone but no chalcone synthase activity [14].
• Since the sublines resistant to chalcone and to RMI-15,731 have little or no capability to bind to chalcone, the resistance to these agents is conferred by changes in the viral capsid protein [15].

Biological context of chalcone

• RNA-mediated RNA degradation and chalcone synthase A silencing in petunia [6].
• Identification and genetic regulation of the chalcone synthase multigene family in pea [16].
• Four short nucleotide sequences (boxes I to IV) contribute to the light responsiveness of the parsley chalcone synthase promoter [17].
• Regulatory properties of a 1.4-kilobase promoter fragment of the bean chalcone synthase CHS8 gene were examined by analysis of glucuronidase (GUS) activity in transgenic tobacco containing a CHS8-GUS gene fusion [18].
• Tissue-specific gene silencing mediated by a naturally occurring chalcone synthase gene cluster in Glycine max [19].

Anatomical context of chalcone

• We have combined in vivo genomic footprinting and light-induced transient expression of chalcone synthase promoter derivatives in parsley protoplasts to identify cis sequences regulating light activation [20].
• The presence of chalcone synthase on these membranes was not caused by nonspecific adsorption or entrapment of proteins [21].
• Biochemical, immunological, and immunocytochemical evidence for the association of chalcone synthase with endoplasmic reticulum membranes [21].
• Addition of MeJA to soybean suspension cultures also increased mRNA levels for three wound-responsive genes (chalcone synthase, vegetative storage protein, and proline-rich cell wall protein) suggesting a role for MeJA/JA in the mediation of several changes in gene expression associated with the plants' response to wounding [22].
• Immunocytochemical investigations with both a 5-nm and a 20-nm ImmunoGold conjugate showed that chalcone synthase was associated with the cytoplasmic face of rough (ribosome bearing) endoplasmic reticulum membranes [21].

Associations of chalcone with other chemical compounds

• Glutathione and a UV light-induced glutathione S-transferase are involved in signaling to chalcone synthase in cell cultures [23].
• RNA expression analysis of ripening fruit revealed that, with the exception of chalcone isomerase, all of the structural genes required for the production of kaempferol-type flavonols and pelargonidin-type anthocyanins were induced strongly by the LC/C1 transcription factors [24].
• Enzyme activity measurement and immunoblots of buckwheat hypocotyl homogenates that were fractionated on linear sucrose density gradients and developed with a specific chalcone synthase antibody and a 20-nm ImmunoGold conjugate showed the presence of chalcone synthase in fractions enriched in endoplasmic reticulum membranes [21].
• RNA blot hybridization with 32P-labeled cDNA sequences was used to demonstrate marked accumulation of phenylalanine ammonia-lyase and chalcone synthase mRNAs in excision-wounded hypocotyls of Phaseolus vulgaris L [25].
• Stilbene (STS) and chalcone (CHS) synthases are homodimeric, related plant-specific polyketide synthases [26].

Gene context of chalcone

• Analysis of gene expression in etiolated seedlings exposed to white light and in two putative regulatory mutants, ttg and tt8, demonstrated that the Arabidopsis F3H gene is coordinately expressed with chalcone synthase and chalcone isomerases is seedlings, whereas dihydroflavonol reductase expression is controlled by distinct regulatory mechanisms [27].
• Together with chalcone polyketide reductase and cytochrome P450 2-hydroxyisoflavanone synthase, the chalcone isomerase (CHI) of leguminous plants is fundamental in the construction of these ecophysiologically active flavonoids [28].
• Other families include the prokaryotic AKRs, the plant chalcone reductases, the Shaker channels, and the ethoxyquin-inducible aflatoxin B1 aldehyde reductase [29].
• 2. At 10 microM, the prenylated chalcone, xanthohumol (XN), almost completely inhibited the 7-ethoxyresorufin O-deethylase (EROD) activity of CYP1A1 [30].
• An enhancement in Fas/APO-1 and its two form ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), was responsible for the apoptotic effect induced by chalcone [31].

Analytical, diagnostic and therapeutic context of chalcone

• Inducible in vivo DNA footprints define sequences necessary for UV light activation of the parsley chalcone synthase gene [32].
• After sequence analysis of the biosynthetic gene cluster, one gene, dpgA, for a predicted polyketide synthase (PKS) was identified, sharing 20-30% identity with plant chalcone synthases [33].
• The role of cysteines in polyketide synthases. Site-directed mutagenesis of resveratrol and chalcone synthases, two key enzymes in different plant-specific pathways [34].
• The apparent molecular weight of the chalcone isomerase is 24,000 as determined from sodium dodecyl sulfate-polyacrylamide gels and from size exclusion chromatography under native conditions on Sephacryl S-200 [35].
• Molecular cloning of chalcone synthase cDNAs from Pisum sativum [36].

References