Disease relevance of plc

• To assess what roles the active site residues Glu4 and Asp55 of the phosphatidylcholine-preferring phospholipase C of Bacillus cereus (PLCBc) might play in binding and catalysis, selected mutants were prepared through site-directed mutagenesis of the plc gene [1].
• The gene for PI-PLC (plc) was cloned from S. aureus into Escherichia coli [2].
• Amino acid sequence comparisons indicated that the staphylococcal plc gene was similar (51 to 56%) to the PI-PLCs from Bacillus cereus, Bacillus thuringiensis, and Listeria monocytogenes [2].
• Hemolysis by B. cereus results largely from the action of phosphatidylcholine-specific phospholipase C (PC-PLC) and sphingomyelinase (SPH), encoded by the plc and sph genes, respectively [3].
• The plc gene encoding the alpha-toxin (phospholipase C), an important virulence factor of Clostridium perfringens, has been cloned, sequenced and expressed in Escherichia coli [4].

Psychiatry related information on plc

• When phospholipase C is added to a suspension of large unilamellar vesicles of egg phosphatidylcholine, maximal rates of hydrolysis occur only after a latency period [5].

High impact information on plc

• The phosphatidylcholine-hydrolysing phospholipase C (PLC) from Bacillus cereus, a monomeric protein containing 245 amino-acid residues, is similar to some of the corresponding mammalian proteins [6].
• This, together with the fact that the bacterial enzyme can mimic the action of mammalian PLC in causing, for example, enhanced prostaglandin biosynthesis, suggests that B. cereus PLC can be used as a model for the hitherto poorly characterized mammalian PLCs [6].
• Phospholipase C from Bacillus cereus was purified to homogeneity as judged by analytical and sodium dodecyl sulphate disc gel electrophoresis and by immunoelectrophoresis [7].
• The effect of phospholipase C on human blood platelets [7].
• Crystal structure of the phosphatidylinositol-specific phospholipase C from Bacillus cereus in complex with myo-inositol [8].

Chemical compound and disease context of plc

• The phosphatidylglycerol phosphate was made available to the surfactant enzyme in a coupled assay by hydrolysis of cardiolipin [1-(3-sn-phosphatidyl)-3-(3-sn-phosphatidyl)-sn-glycerol] by stereospecific cleavage with phospholipase C (phosphatidylcholine cholinephosphohydrolase, EC 3.1.4.3) from Bacillus cereus [9].
• Incubation with Bacillus cereus PC- or phosphatidylinositol-specific phospholipase C, which increased DAG but not phosphatidic acid, stimulated translocation of PKC epsilon, but not PKC alpha or zeta [10].
• Under the conditions employed, cholesterol oxidase of Nocardia erythropolis and phospholipase C of Bacillus cereus were shown to completely modify their substrates in the virus without altering virus-associated hemagglutinating and neuraminidase activities [11].
• Mammalian cells that express Bacillus cereus phosphatidylinositol-specific phospholipase C have increased levels of inositol cyclic 1:2-phosphate, inositol 1-phosphate, and inositol 2-phosphate [12].
• We demonstrate here, by exogenous addition of Bacillus cereus phosphatidylcholine-hydrolyzing phospholipase C, that phosphatidylcholine breakdown mimics the ability of carbachol to inhibit adenylate cyclase [13].

Biological context of plc

• Transfection with an antisense plc expression vector led to a loss of PC-PLC expression accompanied by a complete reversion of the transformed phenotype, suggesting that plc expression was required for maintenance of the transformed state [14].
• The NIH 3T3 clones expressing plc induced DNA synthesis, progressed through the cell cycle in the absence of added mitogens, and showed significant growth in low-concentration serum [14].
• We found that constitutive expression of this gene (plc) led to transformation of NIH 3T3 cells as evidenced by anchorage-independent growth in soft agar, formation of transformed foci in tissue culture, and loss of contact inhibition [14].
• Polymerase chain reaction (PCR) mutagenesis on the PLCBc gene (plc) was then used to replace the Glu146 codon with those for glutamine (E146Q), aspartic acid (E146D), histidine (E146H), and leucine (E146L) [15].
• We have examined the effects of phospholipase C from Bacillus cereus on the extent of phospholipid hydrolysis in envelope membrane vesicles and in intact chloroplasts [16].

Anatomical context of plc

• Comparing the results of conventionally used egg yolk turbidity assay and those gained with DNA hybridization, the plc probe proved to be a much more sensitive and specific diagnostic tool for the detection of C.perfringens plc [17].
• On the contrary, phosphatidylglycerol, the major polar lipid in the inner envelope membrane and the thylakoids, is probably not accessible to phospholipase C from the cytosol and therefore is probably localized mostly in the inner leaflet of the outer envelope membrane and in the other chloroplast membranes [16].
• The toxin is a 370-residue, zinc metalloenzyme that has phospholipase C activity, and can bind to membranes in the presence of calcium [18].
• Membrane phospholipids of erythrocyte ghosts treated with Ca2+ and phosphate ions become exposed to attack by phospholipase C (phosphatidylcholine cholinephosphohydrolase, EC 3.1.4.3) (Bacillus cereus) [19].
• Butanol extraction of the plasma membranes at pH 7.6 yielded a water-soluble, aggregated form that PI phospholipase C could also convert to dimers [20].

Associations of plc with chemical compounds

• The plc transfectants displayed increased intracellular levels of diacylglycerol and phosphocholine [14].
• Role of GTPase activating protein in mitogenic signalling through phosphatidylcholine-hydrolysing phospholipase C [21].
• PC-PLC treatment did not induce tyrosine phosphorylation or turnover of the CSF-1 receptor [22].
• We find that the phospholipase C (C. perfringens) preferentially hydrolyzes phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin leaving the negatively charged phospholipids, phosphatidylserine and phosphatidylinositol, intact [23].
• These results strongly suggest that the phosphate headgroup of PG is cleaved off by PLC as 1,3-cyclic glycerophosphate [24].

Analytical, diagnostic and therapeutic context of plc

• Human platelets isolated from platelet-rich plasma by gel filtration or by centrifugation and washing were incubated with phospholipase C. A loss of 20-45% of the total platelet phospholipid was observed, whereas 88% was hydrolyzed when platelet homogenates were submitted to identical enzyme treatment [7].
• Binding of phospholipase C to pure detergent micelles is demonstrated by gel filtration chromatography [25].
• Thin section electron microscopy reveals gross morphological changes in phospholipase C-treated sarcolemma [23].
• Filtration through Sepharose 6B of solubilized 125I-choriogonadotropin-receptor complex from untreated membranes or membranes which had been pretreated with phospholipase C prior to carrying out hormone binding did not alter the profile (Kav 0.38) [26].
• After treatment of the membrane fraction with the S. aureus phospholipase C the dipeptidase was converted from an amphipathic to a hydrophilic form, as deduced from phase-separation experiments in Triton X-114 [27].

References