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)

A 60-kDa protein homologous to phosphoinositide-specific phospholipase C-alpha was purified to apparent homogeneity on sodium dodecyl sulfate-polyacrylamide gel electrophoresis from the rough endoplasmic reticulum of rat liver through three sequential chromatographies on DEAE Toyopearl 650, AF-heparin Toyopearl 650M, and TSK gel G3000SW. The purified protein was monomeric, with an M(r) of 60,000. Eight types of protein were further separated from the 60-kDa protein and named ER60A-ER60H according to the order of their elution from a TSK gel DEAE-5PW column. They were essentially identical in terms of immunochemical properties and the NH2-terminal amino acid sequence. The partial amino acid sequence of ER60F showed homology to that of phosphoinositide-specific phospholipase C-alpha. ER60A-ER60H showed no phosphoinositide-specific phospholipase C activity. However, ER60A-ER60H catalyzed cleavage of themselves and the endoplasmic reticulum proteins protein disulfide-isomerase and calreticulin. Proteolytic degradation was inhibited by p-chloromercuribenzoate. These results indicate that ER60A-ER60H comprise a group of endoplasmic reticulum resident proteins and show thiol group-related proteolytic activity.
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PMID:Protein degradation by the phosphoinositide-specific phospholipase C-alpha family from rat liver endoplasmic reticulum. 132 29

cDNA clones containing sequence similarity to the multifunctional vertebrate protein disulfide-isomerase (PDI, EC 5.3.4.1) were isolated from an alfalfa (Medicago sativa L.) cDNA library by screening with a cDNA sequence encoding human PDI. The polypeptide encoded by a clone designated B2 consisted of 512 amino acids and was characterized by a 24-amino acid hydrophobic leader sequence, two regions with absolute identity to the vertebrate PDI active site (Ala-Pro-Trp-Cys-Gly-His-Cys-Lys), and a C-terminal endoplasmic reticulum retention signal (Lys-Asp-Glu-Leu). The overall identity of the B2 sequence to that of human PDI was 35% at the amino acid level (79% when conservative substitutions were included) and 39% at the nucleotide level; this included homology between B2 and the region of human PDI believed to be involved in binding estrogens. The deduced amino acid sequence of B2 was also 35% identical to that of a rat form I phosphatidylinositol-specific phospholipase C. Lysates from Escherichia coli cells harboring an expression plasmid bearing the B2 sequence contained significantly elevated levels of PDI activity. Southern analysis indicated the presence of a small PDI-related gene family in alfalfa, of which B2 appeared to correspond to a single gene. An approximately 2-kilobase B2 transcript was expressed in all alfalfa organs tested. In alfalfa cell suspension cultures, B2 transcripts were strongly induced by tunicamycin but not by exposure to fungal elicitor.
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PMID:Molecular cloning of a putative plant endomembrane protein resembling vertebrate protein disulfide-isomerase and a phosphatidylinositol-specific phospholipase C. 172 May 55

We recently showed that when rats were administered the inhalation anesthetic halothane, a 58 kDa liver endoplasmic reticulum protein became covalently trifluoroacetylated by the trifluoroacetyl chloride metabolite of halothane. Although the 58 kDa protein showed 99% identity to that of the deduced amino acid sequence of a cDNA reported to correspond to phosphatidylinositol-specific phospholipase C-alpha, it did not have phosphatidylinositol-specific phospholipase C activity. It was concluded that the reported cDNA of phosphatidylinositol-specific phospholipase C-alpha actually encoded for the 58 kDa endoplasmic reticulum protein of unknown function. Other researchers have come to the same conclusion and have shown that the 58 kDa protein has protein disulfide-isomerase and protease activities. We now report that patients with halothane hepatitis have serum antibodies that react with both purified trifluoroacetylated and native rat liver 58 kDa proteins. These results suggest that when patients are exposed to halothane a human liver orthologue of the rat liver trifluoroacetylated-58 kDa protein is formed. In certain patients, this protein may become immunogenic and lead to the formation of specific antibodies and or specific T-cells, which may react with both trifluoroacetylated and native 58 kDa proteins, and ultimately be responsible, at least in part, for the hepatitis caused by halothane.
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PMID:Association of anti-58 kDa endoplasmic reticulum antibodies with halothane hepatitis. 821 76