Biomaterial Database

Difference in F-actin depolymerization induced by toxin B from the Clostridium difficile strain VPI 10463 and toxin B from the variant Clostridium difficile serotype F strain 1470. 2013

Martin May, and Tianbang Wang, and Micro Müller, and Harald Genth

Institute of Toxicology Hannover Medical School, Hannover D-30625, Germany. martinmay@gmx.de

Clostridium difficile toxin A (TcdA) and toxin B (TcdB) are the causative agent of the C. difficile-associated diarrhea (CDAD) and its severe form, the pseudomembranous colitis (PMC). TcdB from the C. difficile strain VPI10463 mono-glucosylates (thereby inactivates) the small GTPases Rho, Rac, and Cdc42, while Toxin B from the variant C. difficile strain serotype F 1470 (TcdBF) specifically mono-glucosylates Rac but not Rho(A/B/C). TcdBF is related to lethal toxin from C. sordellii (TcsL) that glucosylates Rac1 but not Rho(A/B/C). In this study, the effects of Rho-inactivating toxins on the concentrations of cellular F-actin were investigated using the rhodamine-phalloidin-based F-actin ELISA. TcdB induces F-actin depolymerization comparable to the RhoA-inactivating exoenzyme C3 from C. limosum (C3-lim). In contrast, the Rac-glucosylating toxins TcdBF and TcsL did not cause F-actin depolymerization. These observations led to the conclusion that F-actin depolymerization depends on the toxin's capability of glucosylating RhoA. Furthermore, the integrity of focal adhesions (FAs) was analyzed using paxillin and p21-activated kinase (PAK) as FA marker proteins. Paxillin dephosphorylation was observed upon treatment of cells with TcdB, TcdBF, or C3-lim. In conclusion, the Rho-inactivating toxins induce loss of cell shape by either F-actin depolymerization (upon RhoA inactivation) or the disassembly of FAs (upon Rac1 inactivation).

UI	MeSH Term	Description	Entries
D004797	Enzyme-Linked Immunosorbent Assay	An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.	ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D005260	Female		Females
D006031	Glycosylation	The synthetic chemistry reaction or enzymatic reaction of adding carbohydrate or glycosyl groups. GLYCOSYLTRANSFERASES carry out the enzymatic glycosylation reactions. The spontaneous, non-enzymatic attachment of reducing sugars to free amino groups in proteins, lipids, or nucleic acids is called GLYCATION (see MAILLARD REACTION).	Protein Glycosylation,Glycosylation, Protein
D006367	HeLa Cells	The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for, among other things, VIRUS CULTIVATION and PRECLINICAL DRUG EVALUATION assays.	Cell, HeLa,Cells, HeLa,HeLa Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000199	Actins	Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.	F-Actin,G-Actin,Actin,Isoactin,N-Actin,alpha-Actin,alpha-Isoactin,beta-Actin,gamma-Actin,F Actin,G Actin,N Actin,alpha Actin,alpha Isoactin,beta Actin,gamma Actin
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D001427	Bacterial Toxins	Toxic substances formed in or elaborated by bacteria; they are usually proteins with high molecular weight and antigenicity; some are used as antibiotics and some to skin test for the presence of or susceptibility to certain diseases.	Bacterial Toxin,Toxins, Bacterial,Toxin, Bacterial
D012703	Serotyping	Process of determining and distinguishing species of bacteria or viruses based on antigens they share.	Serotypings