Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.3 (phospholipase C)
 18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The uptake into isolated HeLa nuclei of radioactive cytosol proteins and purified Escherichia coli ribosomal protein L7 is stimulated up to 4-fold by pancreatic deoxyribonuclease (DNase I). Similar effects are not observed with pancreatic ribonuclease A or phospholipase C. The results reported suggest that there is a general stimulatory effect of DNase on protein uptake by nuclei.
 ...
PMID:Stimulation of the uptake of soluble proteins into isolated HeLa nuclei by pancreatic deoxyribonuclease. 111 88

We have previously shown that exposure of responding cells to vitamin A leads to profound modifications of chromatin structure as revealed by an increased susceptibility to DNase I digestion, modified patterns of histone acetylation, and impaired synthesis of a nonhistone chromosomal protein (Ferrari, N., and Vidali, G. (1985) Eur. J. Biochem. 151, 305-310). The present results show that these effects are most probably due to the direct interaction between retinol and chromatin, and analysis of mononucleosomes and higher oligomers obtained from retinol-treated cells shows that retinol is indeed tightly bound to chromatin. Enzymatic digestions of vitamin A containing nucleosomes with proteinase K, phospholipase C, and phospholipase A2 support a model where the final binding of retinol to chromatin is mediated by a lipoprotein: the recognition of the binding sites on DNA being dictated by the proteic component while the hydrophobic retinol is solubilized in the fatty acid moiety.
 ...
PMID:In vivo binding of retinol to chromatin. The binding is mediated by a lipoprotein. 333 5

We studied the interaction between the purified membrane fraction of human platelets and the polymerization of skeletal actin. The viscosity of actin was measured by the falling ball method. The fraction suppressed the polymerization of actin in the presence of 20 mM KCl and 0.4 mM EGTA. The addition of calcium ion or thrombin to the fraction did not cause suppression. A DNase I affinity column bound the membrane fraction in the presence of calcium ion. The frozen membrane fraction and the vesicles reconstituted with lipids from the platelet membrane enhanced the polymerization of actin. Trypsinized membrane fraction and the membrane fraction treated with phospolipase A2 enhanced the polymerization of actin, but membrane fraction treated with phospholipase C had no effect. The reconstituted membrane vesicles mentioned above lowered the critical concentration for actin polymerization. These findings suggested that the polymerization of intracellular actin is enhanced not only by the mobilization of calcium ion, but also by biochemical changes in the membrane lipids.
 ...
PMID:Regulation of actin polymerization by membrane fraction of platelets. 336 64

A simple purification method for pancreatic deoxyribonuclease I (DNase I) [EC 3.1.4.3] was developed by utilizing the technique of isoelectric focusing. The active protein was resolved in to at least four forms with different isoelectric points; the major components a, b, and c had isoelectric points at pH 5.2, 4.9, and 4.8, respectively, and that of the minor component d was at 4.7. The four components (a, b, c, and d) exhibited peaks similar to those observed by Salnikow et al. after phosphocellulose chromatography (A, B, C, and D). The four components were all free from RNase and protease activities and were very stable at 0-2 degrees C for at least four weeks. Further, each of the four peaks exhibited a single protein band after polyacrylamide electrophoresis. DNase I-a antibody was prepared; it was very specific for DNase I and precipitated with the other components (b, c, and d). The mode of endonucleolytic action of pancreatic DNase I-a purified from Worthington DP grade DNase I was investigated. The sedimentation patterns in neutral sucrose gradients of digest of circular duplex DNA in an early stage of hydrolysis suggested that DNase I produces single strand scissions in the initial attack in the presence of divalent metal ions.
 ...
PMID:Simple purification and properties of bovine pancreatic deoxyribonuclease I. 625 39

The 5'-upstream region of the rat phospholipase C-beta 3 gene (PLC-beta 3) has been cloned and characterized. Sequence analysis of the 5'-upstream region showed that it contains a GC-rich region (-166 to +1: 79%) and multiple binding sites for the transcription factors Sp1, AP-1 and AP-2, but does not contain a canonical TATA box. Primer extension analysis of total RNA isolated from rat glial cell C6Bul revealed that single transcription start point (tsp) is located at an initiator (Inr) element similar to that found in the HIV promoter. Gel mobility shift and competitive mobility shift assays indicated that this Inr element forms a DNA-protein complex with the HIV Inr-binding protein, LBP-1/CP2 or a homologue. In order to localize functional elements of the 5'-upstream region of the rat PLC-beta 3 gene, 5'-deletion fragments were cloned into a chloramphenicol acetyltransferase (CAT) reporter vector. Transient transfection analyses of the 5'-deletion mutants identified a crucial promoter element located at -128 to -14. Supershift mobility assays, site-directed mutagenesis and DNase I footprints indicated that Sp1 binds to three GC boxes within the sequence between -128 and -14 of the PLC-beta 3 promoter. Transient transfection analyses of promoter constructs containing site-specific mutation(s) of these three GC boxes demonstrated that two GC boxes, located proximal to the tsp, are important elements for normal promoter activity.
 ...
PMID:The 5'-upstream region of the rat phospholipase C-beta 3 gene contains two critical Sp1 sites and an HIV Inr-like element. 933 46

1. The role of actin polymerization in the regulation of smooth muscle contractility was investigated in canine trachealis muscle strips. The effect of contractile activation on the content of monomeric globular (G)-actin was estimated by the method of DNase I inhibition. The G-actin content was 30 % lower in extracts of muscle strips activated with 10-4 M acetylcholine (ACh) than in extracts from unstimulated muscle strips. The decrease in G-actin in response to contractile stimulation was prevented by latrunculin-A, an agent that prevents actin polymerization by binding to G-actin monomers. 2. The inhibition of actin polymerization by latrunculin-A markedly depressed force development in response to ACh but had no effect on ACh-induced myosin light chain (MLC) phosphorylation. Latrunculin also suppressed the length sensitivity of force during ACh-induced isometric contractions. The actin-capping agent cytochalasin-D also markedly inhibited force and caused only a slight decrease in MLC phosphorylation. Cytochalasin-D also inhibited force in alpha-toxin-permeabilized muscle strips that were activated either by Ca2+ or by ACh at constant pCa. No disorganization of smooth muscle cell ultrastructure was detected by electron microscopy or by immunofluorescence microscopy of muscles treated with either agent. 3. The results suggest that the polymerization of actin is stimulated by the contractile activation of tracheal smooth muscle and that this actin polymerization contributes directly to force development. In addition, actin filament remodelling contributes to the length sensitivity of tracheal smooth muscle contractility.
 ...
PMID:Actin polymerization stimulated by contractile activation regulates force development in canine tracheal smooth muscle. 1045 94

Regulation of toxin production in the gram-positive anaerobe Clostridium perfringens occurs at the level of transcription and involves a two-component signal transduction system. The sensor histidine kinase is encoded by the virS gene, while its cognate response regulator is encoded by the virR gene. We have constructed a VirR expression plasmid in Escherichia coli and purified the resultant His-tagged VirR protein. Gel mobility shift assays demonstrated that VirR binds to the region upstream of the pfoA gene, which encodes perfringolysin O, but not to regions located upstream of the VirR-regulated plc, colA, and pfoR genes, which encode alpha-toxin, collagenase, and a putative pfoA regulator, respectively. The VirR binding site was shown by DNase I footprinting to be a 52-bp core sequence situated immediately upstream of the pfoA promoter. When this region was deleted, VirR was no longer able to bind to the pfoA promoter. The binding site was further localized to two imperfect direct repeats (CCCAGTTNTNCAC) by site-directed mutagenesis. Binding and protection analysis of these mutants indicated that VirR had the ability to bind independently to the two repeated sequences. Based on these observations it is postulated that the VirR positively regulates the synthesis of perfringolysin O by binding directly to a region located immediately upstream of the pfoA promoter and activating transcription.
 ...
PMID:The VirR response regulator from Clostridium perfringens binds independently to two imperfect direct repeats located upstream of the pfoA promoter. 1061 63

More than 200 direct CodY target genes in Staphylococcus aureus were identified by genome-wide analysis of in vitro DNA binding. This analysis, which was confirmed for some genes by DNase I footprinting assays, revealed that CodY is a direct regulator of numerous transcription units associated with amino acid biosynthesis, transport of macromolecules, and virulence. The virulence genes regulated by CodY fell into three groups. One group was dependent on the Agr system for its expression; these genes were indirectly regulated by CodY through its repression of the agr locus. A second group was regulated directly by CodY. The third group, which includes genes for alpha-toxin and capsule synthesis, was regulated by CodY in two ways, i.e., by direct repression and by repression of the agr locus. Since S. aureus CodY was activated in vitro by the branched chain amino acids and GTP, CodY appears to link changes in intracellular metabolite pools with the induction of numerous adaptive responses, including virulence.
 ...
PMID:Direct targets of CodY in Staphylococcus aureus. 2036 36

HutC is known as a transcriptional repressor specific for histidine utilization (hut) genes in Gram-negative bacteria, including Pseudomonas fluorescens SBW25. However, its precise mode of protein-DNA interactions hasn't been examined with purified HutC proteins. Here, we performed electrophoretic mobility shift assay (EMSA) and DNase I footprinting using His6-tagged HutC and biotin-labeled probe of the hut promoter (PhutU). Results revealed a complex pattern of HutC oligomerization, and the specific protein-DNA interaction is disrupted by urocanate, a histidine derivative, in a concentration-dependent manner. Next, we searched for putative HutC-binding sites in the SBW25 genome. This led to the identification of 143 candidate targets with a P value less than 10-4 HutC interaction with eight selected candidate sites was subsequently confirmed by EMSA analysis, including the type IV pilus assembly protein PilZ, phospholipase C (PlcC) for phosphatidylcholine hydrolyzation, and key regulators of cellular nitrogen metabolism (NtrBC and GlnE). Finally, an isogenic hutC deletion mutant was subjected to transcriptome sequencing (RNA-seq) analysis and phenotypic characterization. When bacteria were grown on succinate and histidine, hutC deletion caused upregulation of 794 genes and downregulation of 525 genes at a P value of <0.05 with a fold change cutoff of 2.0. The hutC mutant displayed an enhanced spreading motility and pyoverdine production in laboratory media, in addition to the previously reported growth defect on the surfaces of plants. Together, our data indicate that HutC plays global regulatory roles beyond histidine catabolism through low-affinity binding with operator sites located outside the hut locus.IMPORTANCE HutC in Pseudomonas is a representative member of the GntR/HutC family of transcriptional regulators, which possess a N-terminal winged helix-turn-helix (wHTH) DNA-binding domain and a C-terminal substrate-binding domain. HutC is generally known to repress expression of histidine utilization (hut) genes through binding to the PhutU promoter with urocanate (the first intermediate of the histidine degradation pathway) as the direct inducer. Here, we first describe the detailed molecular interactions between HutC and its PhutU target site in a plant growth-promoting bacterium, P. fluorescens SBW25, and further show that HutC possesses specific DNA-binding activities with many targets in the SBW25 genome. Subsequent RNA-seq analysis and phenotypic assays revealed an unexpected global regulatory role of HutC for successful bacterial colonization in planta.
 ...
PMID:Global Regulatory Roles of the Histidine-Responsive Transcriptional Repressor HutC in Pseudomonas fluorescens SBW25. 3229 Dec 79