Cytotoxicity of KDEL-terminated ricin toxins correlates with distribution of the KDEL receptor in the GolgiE Tagge, J Chandler, BL Tang, W Hong, MC Willingham and A Frankel Department of Surgery, Medical University of South Carolina, Charleston, USA. DNAs encoding ricin toxin A chain (RTA), with or without a C-terminal endoplasmic reticulum retention signal KDEL, were subcloned into pGEX2T bacterial expression plasmid. After transformation of JM105 E. coli cells and induction with isopropylthio-beta-galactoside (IPTG), fusion proteins were bound to an immobilized glutathione matrix and recombinant ricin A chains released with thrombin. Both recombinant wild-type RTA and RTA with KDEL had immunological reactivity and catalytic activity indistinguishable from plant RTA. The bacterial RTA products reassociated with plant ricin B chain (RTB) similarly to plant RTA. Cell cytotoxicities were measured on seven cell lines for each A- chain and heterodimer. Although KDEL sequences enhanced cytotoxicity in most cases, significant variability was observed. In each case, addition of KDEL enhanced A-chain cytotoxicity more than holotoxin cytotoxicity. Three cell lines showed reduced KDEL enhancement of both RTA and ricin cytotoxicity. The concentration of KDEL receptor was examined on each cell line by immunofluorescence microscopy with an antireceptor monoclonal antibody. Differences in sensitivity to KDEL- containing toxins correlated with altered distribution of KDEL receptor between endoplasmic reticulum (ER) and Golgi compartments.
Volume 44,
Issue 2,
pp. 159-165,
02/01/1996
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
![]() |
M. C. Haigis and R. T. Raines Secretory ribonucleases are internalized by a dynamin-independent endocytic pathway J. Cell Sci., January 15, 2003; 116(2): 313 - 324. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Rajagopal and R. J. Kreitman Recombinant Toxins That Bind to the Urokinase Receptor Are Cytotoxic without Requiring Binding to the alpha 2-Macroglobulin Receptor J. Biol. Chem., March 10, 2000; 275(11): 7566 - 7573. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Wesche, A. Rapak, and S. Olsnes Dependence of Ricin Toxicity on Translocation of the Toxin A-chain from the Endoplasmic Reticulum to the Cytosol J. Biol. Chem., November 26, 1999; 274(48): 34443 - 34449. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Rapak, P. O. Falnes, and S. Olsnes Retrograde transport of mutant ricin to the endoplasmic reticulum with subsequent translocation to cytosol PNAS, April 15, 1997; 94(8): 3783 - 3788. [Abstract] [Full Text] [PDF] |
||||
| Guidelines | Subscriptions | About | exPRESS - Current - Archive | Business Information | Contact |