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)

We have recently generated a series of gamma/delta T cell clones able to kill, after in vitro immunization, an Epstein-Barr Virus-transformed B cell line (designated E418) in a non-major histocompatibility complex-requiring fashion. A monoclonal antibody, termed anti-10H3, produced against E418 was selected by its ability to block these cytotoxic interactions. Further analysis indicated that the inhibitory effects of anti-10H3 were highly selective (i.e., no blocking activity with multiple control clones used as effector cells; no alteration of the natural killer-like function mediated by the relevant gamma/delta clones against 10H3+ tumor cells such as Rex). The molecule immunoprecipitated by anti-10H3, termed TCT.1, was characterized as a 43-kD protein broadly distributed in the hematopoietic system. The TCT.1 molecule has been further studied here by protein microsequencing. Results show that the TCT.1-derived peptide sequences are virtually identical to corresponding regions of Blast-1, a previously described surface protein with unknown function. The likely identity of the two molecules has been strengthened by analyzing the susceptibility of TCT.1 to phosphatidylinositol-specific phospholipase C digestion in light of the known anchorage of Blast-1 to the cell membrane through a glycosyl-phosphatidylinositol-containing lipid. The TCT.1/Blast-1-encoding gene is well characterized; it belongs to the immunoglobulin gene superfamily and it is located in the same band of chromosome 1 as the CD1 gene cluster. Together, these data further support the view that proteins distinct from the conventional class I/II histocompatibility molecules are involved in specific T cell recognition.
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PMID:TCT.1, a target molecule for gamma/delta T cells, is encoded by an immunoglobulin superfamily gene (Blast-1) located in the CD1 region of human chromosome 1. 182 26

The lethal and edema-inducing alpha-toxin from Clostridium novyi causes rounding up of cultured cell lines by redistribution of the actin cytoskeleton. alpha-Toxin belongs to the family of large clostridial cytotoxins that encompasses Clostridium difficile toxin A and B and the lethal toxin from Clostridium sordellii. Toxin A and toxin B have been recently identified as monoglucosyltransferases to modify the low molecular mass GTPases of the Rho subfamily (Just, I., Selzer, J., Wilm, M., Von Eichel-Streiber, C., Mann, M., and Aktories, K. (1995) Nature 375, 500-503 and Just, I., Wilm, M., Selzer, J., Rex, G., Von Eichel-Streiber, C., Mann, M., and Aktories, K. (1995) J. Biol. Chem. 270, 13932-13936). We report here the identification of the alpha-toxin-catalyzed modification of Rho. Using electrospray mass spectrometry, the mass of the modification was determined as 203 Da, consistent with a N-acetyl-hexosamine moiety. UDP-N-acetyl-glucosamine selectively served as cosubstrate for alpha-toxin-catalyzed modification into the Rho subfamily proteins Rho, Rac, Cdc42, and RhoG. The acceptor amino acid of N-acetyl-glucosaminylation was identified by mutagenesis as Thr-37 in Rho (equivalent to Thr-35 in Rac/Cdc42), which is located in the effector domain of the GTPases. C. novyi alpha-toxin seems to mediate its cytotoxic effects on cells by mimicking endogenous post-translational modification of cellular proteins.
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PMID:Clostridium novyi alpha-toxin-catalyzed incorporation of GlcNAc into Rho subfamily proteins. 881 Feb 74