title: Rho-modifying bacterial protein toxins from Photorhabdus species.
abstract: Photorhabdus bacteria live in symbiosis with entomopathogenic nematodes. The nematodes invade insect larvae, where they release the bacteria, which then produce toxins to kill the insects. Recently, the molecular mechanisms of some toxins from Photorhabdus luminescens and asymbiotica have been elucidated, showing that GTP-binding proteins of the Rho family are targets. The tripartite Tc toxin PTC5 from P. luminescens activates Rho proteins by ADP-ribosylation of a glutamine residue, which is involved in GTP hydrolysis, while PaTox from Photorhabdus asymbiotica inhibits the activity of GTPases by N-acetyl-glucosaminylation at tyrosine residues and activates Rho proteins indirectly by deamidation of heterotrimeric G proteins.
authors.affiliation: Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jank
authors.affiliation: Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Lang
authors.affiliation: Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany; Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs-Universität Freiburg, Freiburg, Germany. Electronic address: klaus.aktories@pharmakol.uni-freiburg.de.
authors.forename: Klaus
authors.initials: K
authors.lastname: Aktories
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry* / Q000633:toxicity; D007313:Insecta / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D008958:Models, Molecular; D020637:Photorhabdus / Q000378:metabolism*; D000072417:Protein Domains; D020741:rho GTP-Binding Proteins / Q000737:chemistry*
chemical_list: D001427:Bacterial Toxins; D020741:rho GTP-Binding Proteins
keywords: ADP-ribosylation; Actin; Deamidation; Glycosylation; Heterotrimeric G proteins; Membrane binding