The complete receptor-binding domain of Clostridium difficile toxin A is required for endocytosis

被引:47
作者
Frisch, C
Gerhard, R
Aktories, K
Hofmann, F
Just, I
机构
[1] Hannover Med Sch, Inst Toxikol, D-30625 Hannover, Germany
[2] Univ Freiburg, Inst Expt & Klin Pharmakol & Toxikol, D-79104 Freiburg, Germany
关键词
endocytosis; toxin A; receptor; receptor-binding domain;
D O I
10.1016/S0006-291X(02)02919-4
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Clostridium difficile toxin A, the chief pathogenicity factor of the antibiotic-associated pseudomembranous colitis, is an intracellular acting cytotoxin that reaches its targets, the Rho GTPases, after receptor-mediated endocytosis. The C-terminal part, constructed of repetitive peptide elements, is thought to bind to a lot of carbohydrate containing receptor molecules to induce clustering and endocytosis. To study which part of the receptor-binding domain is in charge of addressing toxin A into the target cells, we studied the functional, i.e., endocytosis-inducing, binding of toxin A. By a competition assay between various receptor-binding fragments of toxin A and the holotoxin A we found that the complete receptor-binding domain, encompassing the entire repetitive elements, but not parts of it, is necessary for binding-induced endocytosis. The receptor binding domain itself shows weaker competition with holotoxin A than the fragment consisting of receptor-binding domain plus intermediary part of the toxin. All toxin A fragments that compete with holotoxin A are capable of inducing their own endocytosis. Thus. the entire receptor-binding domain, covering the C-terminal third of the toxin A molecule, is responsible for cell uptake of toxin A and the intermediary part contributes to the correct folding and assembly of the repetitive domains. (C) 2002 Elsevier Science (USA). All rights reserved.
引用
收藏
页码:706 / 711
页数:6
相关论文
共 28 条
[1]   Toxins A and B from Clostridium difficile differ with respect to enzymatic potencies, cellular substrate specificities, and surface binding to cultured cells [J].
ChavesOlarte, E ;
Weidmann, M ;
vonEichelStreiber, C ;
Thelestam, M .
JOURNAL OF CLINICAL INVESTIGATION, 1997, 100 (07) :1734-1741
[2]   CLOSTRIDIUM-DIFFICILE TOXIN-A AND ITS EFFECTS ON CELLS [J].
FIORENTINI, C ;
THELESTAM, M .
TOXICON, 1991, 29 (06) :543-567
[3]   INTERNALIZATION OF CLOSTRIDIUM-DIFFICILE CYTO-TOXIN INTO CULTURED HUMAN-LUNG FIBROBLASTS [J].
FLORIN, I ;
THELESTAM, M .
BIOCHIMICA ET BIOPHYSICA ACTA, 1983, 763 (04) :383-392
[4]   LOCALIZATION OF 2 EPITOPES RECOGNIZED BY MONOCLONAL-ANTIBODY PCG-4 ON CLOSTRIDIUM-DIFFICILE TOXIN-A [J].
FREY, SM ;
WILKINS, TD .
INFECTION AND IMMUNITY, 1992, 60 (06) :2488-2492
[5]   New method to generate enzymatically deficient Clostridium difficile toxin B as an antigen for immunization [J].
Genth, H ;
Selzer, J ;
Busch, C ;
Dumbach, J ;
Hofmann, F ;
Aktories, K ;
Just, I .
INFECTION AND IMMUNITY, 2000, 68 (03) :1094-1101
[6]   Rho GTPases and the actin cytoskeleton [J].
Hall, A .
SCIENCE, 1998, 279 (5350) :509-514
[7]   Bacterial protein toxins inhibiting low-molecular-mass GTP-binding proteins [J].
Just, I ;
Hofmann, F ;
Genth, H ;
Gerhard, R .
INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY, 2001, 291 (04) :243-250
[8]  
Just I, 2000, CURR TOP MICROBIOL, V250, P55
[9]  
Just I., 1997, Bacterial Toxins, P159, DOI [10.1002/9783527614615.ch13, DOI 10.1002/9783527614615.CH13]
[10]   MICROBIAL RECOGNITION OF TARGET-CELL GLYCOCONJUGATES [J].
KARLSSON, KA .
CURRENT OPINION IN STRUCTURAL BIOLOGY, 1995, 5 (05) :622-635