title: Endocytosis and retrograde transport of pertussis toxin to the Golgi complex as a prerequisite for cellular intoxication.
abstract: The uptake mechanism of pertussis toxin (PT) in CHO and insulin-producing HIT-T15 cells was studied. By electron microscopy after direct labeling of the toxin with gold particles, PT was found to be taken up by receptor-mediated endocytosis. The presence of active pertussis toxin in the Golgi complex was shown by subcellular fractionation. The importance of the Golgi localization of pertussis toxin for the S1-dependent ADP-ribosylation of G-proteins was investigated employing Brefeldin A (BFA) treatment to disrupt Golgi structures. Treatment with Brefeldin A completely blocked the pertussis toxin mediated ADP-ribosylation of cellular G-proteins in CHO and HIT-T15 cells, whereas the BFA-resistant MDCK cells were not protected. A mutant CHO cell line (V24.1) exhibiting a temperature-sensitive Golgi complex could be protected when grown at restrictive conditions. These results strongly indicate that retrograde transport to the Golgi network is a necessary prerequisite for pertussis toxin mediated ADP-ribosylation of G-proteins and thus also for cellular intoxication.
authors.affiliation: Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung (ZMBE) der Westfälischen Wilhelms-Universität, Münster/Germany.
authors.forename: A
authors.initials: A
authors.lastname: el Bayâ
authors.forename: R
authors.initials: R
authors.lastname: Linnemann
authors.forename: L
authors.initials: L
authors.lastname: von Olleschik-Elbheim
authors.forename: H
authors.initials: H
authors.lastname: Robenek
authors.forename: M A
authors.initials: MA
authors.lastname: Schmidt
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D020126:Brefeldin A; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003517:Cyclopentanes / Q000494:pharmacology; D004285:Dogs; D004705:Endocytosis / Q000187:drug effects*; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D009154:Mutation / Q000187:drug effects / Q000502:physiology; D037342:Pertussis Toxin; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D013696:Temperature; D010566:Virulence Factors, Bordetella / Q000494:pharmacology / Q000633:toxicity*
chemical_list: D003517:Cyclopentanes; D010566:Virulence Factors, Bordetella; D020126:Brefeldin A; D000246:Adenosine Diphosphate Ribose; D037342:Pertussis Toxin