Clostridium perfringens TpeL Induces Formation of Stress Fibers via Activation of RhoA-ROCK Signaling Pathway

• Published in: Biological & pharmaceutical bulletin 2015/05/01, Vol.38(5), pp.732-739
• Main Authors: Nagahama, Masahiro, Ohkubo, Akiko, Kinouchi, Yoshihito, Kobayashi, Keiko, Miyamoto, Kazuaki, Takehara, Masaya, Sakurai, Jun
• Format: Article
• Language: English
• Subjects: Actins - metabolism; Amides - pharmacology; Animals; Bacterial Toxins - pharmacology; Clostridium Infections - metabolism; Clostridium perfringens; Clostridium perfringens - metabolism; Clostridium perfringens - pathogenicity; Clostridium perfringens TpeL; Dogs; Enzyme Inhibitors - pharmacology; Madin Darby Canine Kidney Cells; Pyridines - pharmacology; rac1 GTP-Binding Protein - metabolism; ras Proteins - metabolism; Rho A-Rho kinase (ROCK); rho-Associated Kinases - metabolism; RhoA; rhoA GTP-Binding Protein - metabolism; Signal Transduction; stress fiber; Stress Fibers - metabolism; Transferases - pharmacology
• ISSN: 0918-6158; 1347-5215
• DOI: 10.1248/bpb.b14-00842

Clostridium perfringens TpeL belongs to a family of large clostridial glucosylating cytotoxins. TpeL modifies Rac1 and Ras subfamily proteins. Herein we report TpeL-induced formation of stress fibers via RhoA-Rho kinase (ROCK) signaling. A recombinant protein (TpeL1–525) derived from the TpeL N-terminal catalytic domain in the presence of streptolysin O (SLO) induced the formation of actin stress fibers in Madin–Darby canine kidney (MDCK) cells in a dose-dependent manner. The RhoA/ROCK pathway is known to control the formation of stress fibers. We examined the role of the RhoA/ROCK pathway in TpeL-induced formation of stress fibers. TpeL1–525-induced formation of stress fibers was inhibited by the ROCK inhibitor, Y27632 and Rho protein inhibitor, C3 transferase. TpeL1–525 activated RhoA and ROCK in a dose-dependent manner. C3 transferase blocked TpeL1–525-induced activation of RhoA and ROCK whereas Y27632 inhibited TpeL-induced activation of ROCK. These results demonstrate for the first time that TpeL induces the formation of stress fibers by activating the RhoA/ROCK signaling pathway.