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

Transmissible gastroenteritis virus was readily adsorbed onto chicken erythrocytes at 4 degrees C. The hemagglutinin thus adsorbed could be eluted from the erythrocytes by incubating in phosphate buffered saline at 37 degrees C. The receptor on chicken erythrocytes for the hemagglutinin was inactivated by neuraminidase and potassium periodate, but not by trypsin, 2-mercaptoethanol and formalin. The hemagglutinin was inactivated by trypsin, papain, pepsin, alpha-amylase, phospholipase C, neuraminidase, formalin, 2-mercaptoethanol, potassium periodate, ethyl ether, chloroform, Tween-80 and beta-propiolactone, but not by sodium deoxycholate and trichlorotrifluoroethane, suggesting that the active component of the hemagglutinin involved glycoproteins. The hemagglutinin was stable at 37 degrees C or lower temperatures but not at 60 degrees C or higher temperatures. The hemagglutinin activity was resistant to ultraviolet irradiation, while the infectivity was very susceptible. The hemagglutinin and the infectivity were readily sedimented by ultracentrifugation at 45,000 x g for 60 minutes. In rate zonal centrifugation of the hemagglutinin preparation on a sucrose density gradient, the hemagglutinin activity showed a sharp peak at 1.19 g/ml coinciding with the peak of infectivity. The activity in the peak fraction seemed to be structurally associated with virus particles.
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PMID:Physicochemical properties of transmissible gastroenteritis virus hemagglutinin. 283 45

Aerolysin is one of the major virulence factors produced by Aeromonas hydrophila, a human pathogen that produces deep wound infection and gastroenteritis. The toxin interacts with target mammalian cells by binding to the glycan core of glycosylphosphatidyl inositol (GPI)-anchored proteins and subsequently forms a pore in the plasma membrane. Since epithelial cells of the intestine are the primary targets of aerolysin, we investigated its effect on three types of polarized epithelial cells: Caco-2 cells, derived from human intestine; MDCK cells, a well-characterized cell line in terms of protein targeting; and FRT cells, an unusual cell line in that it targets its GPI-anchored proteins to the basolateral plasma membrane in contrast to other epithelial cells, which target them almost exclusively to the apical surface. Surprisingly, we found that all three cell types were sensitive to the toxin from both the apical and the basolateral sides. Apical sensitivity was always higher, even for FRT cells. In contrast, FRT cells were more sensitive from the basolateral than from the apical side to the related toxin Clostridium septicum alpha-toxin, which also binds to GPI-anchored proteins but lacks the lectin binding domain found in aerolysin. These observations are consistent with the notion that a shuttling mechanism involving low-affinity interactions with surface sugars allows aerolysin to gradually move toward the membrane surface, where it can finally encounter the glycan cores of GPI-anchored proteins.
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PMID:Sensitivity of polarized epithelial cells to the pore-forming toxin aerolysin. 1254 May 53

Rotavirus is the major cause of infantile gastroenteritis and each year causes 611,000 deaths worldwide. The virus infects the mature enterocytes of the villus tip of the small intestine and induces a watery diarrhea. Diarrhea can occur with no visible tissue damage and, conversely, the histological lesions can be asymptomatic. Rotavirus impairs activities of intestinal disaccharidases and Na+-solute symports coupled with water transport. Maldigestion of carbohydrates and their accumulation in the intestinal lumen as well as malabsorption of nutrients and a concomitant inhibition of water reabsorption can lead to a malabsorption component of diarrhea. Since the discovery of the NSP4 enterotoxin, diverse hypotheses have been proposed in favor of an additional secretion component in the pathogenesis of diarrhea. Rotavirus induces a moderate net chloride secretion at the onset of diarrhea, but the mechanisms appear to be quite different from those used by bacterial enterotoxins that cause pure secretory diarrhea. Rotavirus failed to stimulate Cl- secretion in crypt, whereas it stimulated Cl- reabsorption in villi, questioning, therefore, the origin of net Cl- secretion. A solution to this riddle was that intestinal villi do in fact secrete chloride as a result of rotavirus infection. Also, the overall chloride secretory response is regulated by a phospholipase C-dependent calcium signaling pathway induced by NSP4. However, the overall response is weak, suggesting that NSP4 may exert both secretory and subsequent anti-secretory actions, as did carbachol, hence limiting Cl- secretion. All these characteristics provide the means to make the necessary functional distinction between viral NSP4 and bacterial enterotoxins.
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PMID:How do the rotavirus NSP4 and bacterial enterotoxins lead differently to diarrhea? 1737 32

Clostridium perfringens causes food-borne gastroenteritis following the consumption of contaminated food by producing C. perfringens enterotoxin (CPE) in the intestines. Recently, we reported a novel enterotoxin, binary enterotoxin of C. perfringens (BEC) in C. perfringens isolates, which caused two disease outbreaks in Japan. Consequently, in the event of food poisoning outbreaks caused by C. perfringens, it is now necessary to screen for both the cpe and becAB genes by diagnostic PCR. Here, we present a simple multiplex PCR method for simultaneous detection of cpe, becAB and a C. perfringens control locus, phospholipase C (plc). Applying this method, we investigated the prevalence of cpe- or becAB-carrying C. perfringens strains in human stool and bovine rectum swab samples. Using a total of 169 isolates, we found that the percentage of becAB-carrying strains was very small (0.59%), one-tenth that of cpe-carrying strains. The simple method presented in this study with high specificity and sensitivity to C. perfringens will be a useful tool to survey the global prevalence of becAB-carrying C. perfringens strains.
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PMID:Development and application of a multiplex PCR assay for detection of the Clostridium perfringens enterotoxin-encoding genes cpe and becAB. 2729 14

Clostridium perfringens (C. perfringens) is responsible for food-borne gastroenteritis and other infectious diseases, and toxins produced by this bacterium play a key role in pathogenesis. Although various toxins have been described for C. perfringens isolates from humans and animals, prevalence of individual toxins among clinical isolates has not yet been well explored. In the present study, a total of 798 C. perfringens clinical isolates were investigated for prevalence of eight toxin genes and their genetic diversity by PCR, nucleotide sequencing, and phylogenetic analysis. Besides the alpha-toxin gene (plc) present in all the isolates, the most common toxin gene was cpe (enterotoxin) (34.2%), followed by cpb2 (beta2 toxin) (1.4%), netB (NetB) (0.3%), and bec/cpile (binary enterotoxin BEC/CPILE) (0.1%), while beta-, epsilon-, and iota-toxin genes were not detected. Genetic analysis of toxin genes indicated a high level of conservation of plc, cpe, and netB. In contrast, cpb2 was revealed to be considerably divergent, containing at least two lineages. Alpha-toxin among 46 isolates was classified into ten sequence types, among which common types were distinct from those reported for avian isolates. A single isolate with bec/cpile harbored a plc variant containing an insertion of 834-bp sequence, suggesting its putative origin from chickens.
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PMID:Prevalence and Genetic Diversity of Toxin Genes in Clinical Isolates of Clostridium perfringens: Coexistence of Alpha-Toxin Variant and Binary Enterotoxin Genes (bec/cpile). 3117 64