title: Actin as target for modification by bacterial protein toxins.
abstract: Various bacterial protein toxins and effectors target the actin cytoskeleton. At least three groups of toxins/effectors can be identified, which directly modify actin molecules. One group of toxins/effectors causes ADP-ribosylation of actin at arginine-177, thereby inhibiting actin polymerization. Members of this group are numerous binary actin-ADP-ribosylating exotoxins (e.g. Clostridium botulinum C2 toxin) as well as several bacterial ADP-ribosyltransferases (e.g. Salmonella enterica SpvB) which are not binary in structure. The second group includes toxins that modify actin to promote actin polymerization and the formation of actin aggregates. To this group belongs a toxin from the Photorhabdus luminescens Tc toxin complex that ADP-ribosylates actin at threonine-148. A third group of bacterial toxins/effectors (e.g. Vibrio cholerae multifunctional, autoprocessing RTX toxin) catalyses a chemical crosslinking reaction of actin thereby forming oligomers, while blocking the polymerization of actin to functional filaments. Novel findings about members of these toxin groups are discussed in detail.
authors.affiliation: Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Germany. klaus.aktories@pharmakol.uni-freiburg.de
authors.forename: Klaus
authors.initials: K
authors.lastname: Aktories
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Lang
authors.forename: Carsten
authors.initials: C
authors.lastname: Schwan
authors.forename: Hans G
authors.initials: HG
authors.lastname: Mannherz
mesh_terms: D036002:ADP Ribose Transferases / Q000737:chemistry / Q000378:metabolism; D008841:Actin Cytoskeleton / Q000737:chemistry* / Q000378:metabolism; D000246:Adenosine Diphosphate Ribose / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D001120:Arginine / Q000737:chemistry / Q000378:metabolism; D001427:Bacterial Toxins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D058105:Polymerization; D011487:Protein Conformation; D013912:Threonine / Q000737:chemistry / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D000246:Adenosine Diphosphate Ribose; D013912:Threonine; D001120:Arginine; D036002:ADP Ribose Transferases