1
|
Comparative Studies of Actin- and Rho-Specific ADP-Ribosylating Toxins: Insight from Structural Biology. Curr Top Microbiol Immunol 2017; 399:69-86. [PMID: 27540723 DOI: 10.1007/82_2016_23] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mono-ADP-ribosylation is a major post-translational modification performed by bacterial toxins, which transfer an ADP-ribose moiety to a substrate acceptor residue. Actin- and Rho-specific ADP-ribosylating toxins (ARTs) are typical ARTs known to have very similar tertiary structures but totally different targets. Actin-specific ARTs are the A components of binary toxins, ADP-ribosylate actin at Arg177, leading to the depolymerization of the actin cytoskeleton. On the other hand, C3-like exoenzymes are Rho-specific ARTs, ADP-ribosylate Rho GTPases at Asn41, exerting an indirect effect on the actin cytoskeleton. This review focuses on the differences and similarities of actin- and Rho-specific ARTs, especially with respect to their substrate recognition and cell entry mechanisms, based on structural studies.
Collapse
|
2
|
Robb C, Robb M, Nano F, Boraston A. The Structure of the Toxin and Type Six Secretion System Substrate Tse2 in Complex with Its Immunity Protein. Structure 2016; 24:277-84. [DOI: 10.1016/j.str.2015.11.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/04/2015] [Accepted: 11/23/2015] [Indexed: 01/11/2023]
|
3
|
Toda A, Tsurumura T, Yoshida T, Tsumori Y, Tsuge H. Rho GTPase Recognition by C3 Exoenzyme Based on C3-RhoA Complex Structure. J Biol Chem 2015; 290:19423-32. [PMID: 26067270 DOI: 10.1074/jbc.m115.653220] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Indexed: 12/18/2022] Open
Abstract
C3 exoenzyme is a mono-ADP-ribosyltransferase (ART) that catalyzes transfer of an ADP-ribose moiety from NAD(+) to Rho GTPases. C3 has long been used to study the diverse regulatory functions of Rho GTPases. How C3 recognizes its substrate and how ADP-ribosylation proceeds are still poorly understood. Crystal structures of C3-RhoA complex reveal that C3 recognizes RhoA via the switch I, switch II, and interswitch regions. In C3-RhoA(GTP) and C3-RhoA(GDP), switch I and II adopt the GDP and GTP conformations, respectively, which explains why C3 can ADP-ribosylate both nucleotide forms. Based on structural information, we successfully changed Cdc42 to an active substrate with combined mutations in the C3-Rho GTPase interface. Moreover, the structure reflects the close relationship among Gln-183 in the QXE motif (C3), a modified Asn-41 residue (RhoA) and NC1 of NAD(H), which suggests that C3 is the prototype ART. These structures show directly for the first time that the ARTT loop is the key to target protein recognition, and they also serve to bridge the gaps among independent studies of Rho GTPases and C3.
Collapse
Affiliation(s)
- Akiyuki Toda
- From the Department of Bioresource and Environmental Sciences, Faculty of Life Sciences, and
| | - Toshiharu Tsurumura
- From the Department of Bioresource and Environmental Sciences, Faculty of Life Sciences, and the Structural Biology Research Center, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto 603-8555, Japan
| | - Toru Yoshida
- From the Department of Bioresource and Environmental Sciences, Faculty of Life Sciences, and the Structural Biology Research Center, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto 603-8555, Japan
| | - Yayoi Tsumori
- From the Department of Bioresource and Environmental Sciences, Faculty of Life Sciences, and
| | - Hideaki Tsuge
- From the Department of Bioresource and Environmental Sciences, Faculty of Life Sciences, and the Structural Biology Research Center, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto 603-8555, Japan
| |
Collapse
|
4
|
Sung VMH, Tsai CL. ADP-Ribosylargininyl reaction of cholix toxin is mediated through diffusible intermediates. BMC BIOCHEMISTRY 2014; 15:26. [PMID: 25494717 PMCID: PMC4265445 DOI: 10.1186/s12858-014-0026-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Accepted: 11/28/2014] [Indexed: 11/29/2022]
Abstract
Background Cholix toxin is an ADP-ribosyltransferase found in non-O1/non-O139 strains of Vibrio cholera. The catalytic fragment of cholix toxin was characterized as a diphthamide dependent ADP-ribosyltransferase. Results Our studies on the enzymatic activity of cholix toxin catalytic fragment show that the transfer of ADP-ribose to toxin takes place by a predominantly intramolecular mechanism and results in the preferential alkylation of arginine residues proximal to the NAD+ binding pocket. Multiple arginine residues, located near the catalytic site and at distal sites, can be the ADP-ribose acceptor in the auto-reaction. Kinetic studies of a model enzyme, M8, showed that a diffusible intermediate preferentially reacted with arginine residues in proximity to the NAD+ binding pocket. ADP-ribosylarginine activity of cholix toxin catalytic fragment could also modify exogenous substrates. Auto-ADP-ribosylation of cholix toxin appears to have negatively regulatory effect on ADP-ribosylation of exogenous substrate. However, at the presence of both endogenous and exogenous substrates, ADP-ribosylation of exogenous substrates occurred more efficiently than that of endogenous substrates. Conclusions We discovered an ADP-ribosylargininyl activity of cholix toxin catalytic fragment from our studies in auto-ADP-ribosylation, which is mediated through diffusible intermediates. The lifetime of the hypothetical intermediate exceeds recorded and predicted lifetimes for the cognate oxocarbenium ion. Therefore, a diffusible strained form of NAD+ intermediate was proposed to react with arginine residues in a proximity dependent manner. Electronic supplementary material The online version of this article (doi:10.1186/s12858-014-0026-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Vicky M-H Sung
- Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston 02114, MA, USA.
| | | |
Collapse
|
5
|
Ma S, Deng J, Li B, Li X, Yan Z, Zhu J, Chen G, Wang Z, Jiang H, Miao L, Li J. Development of Second-Generation Small-Molecule RhoA Inhibitors with Enhanced Water Solubility, Tissue Potency, and Significant in vivo Efficacy. ChemMedChem 2014; 10:193-206. [DOI: 10.1002/cmdc.201402386] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Indexed: 12/24/2022]
|
6
|
Popoff MR. Bacterial factors exploit eukaryotic Rho GTPase signaling cascades to promote invasion and proliferation within their host. Small GTPases 2014; 5:28209. [PMID: 25203748 DOI: 10.4161/sgtp.28209] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Actin cytoskeleton is a main target of many bacterial pathogens. Among the multiple regulation steps of the actin cytoskeleton, bacterial factors interact preferentially with RhoGTPases. Pathogens secrete either toxins which diffuse in the surrounding environment, or directly inject virulence factors into target cells. Bacterial toxins, which interfere with RhoGTPases, and to some extent with RasGTPases, catalyze a covalent modification (ADPribosylation, glucosylation, deamidation, adenylation, proteolysis) blocking these molecules in their active or inactive state, resulting in alteration of epithelial and/or endothelial barriers, which contributes to dissemination of bacteria in the host. Injected bacterial virulence factors preferentially manipulate the RhoGTPase signaling cascade by mimicry of eukaryotic regulatory proteins leading to local actin cytoskeleton rearrangement, which mediates bacterial entry into host cells or in contrast escape to phagocytosis and immune defense. Invasive bacteria can also manipulate RhoGTPase signaling through recognition and stimulation of cell surface receptor(s). Changes in RhoGTPase activation state is sensed by the innate immunity pathways and allows the host cell to adapt an appropriate defense response.
Collapse
Affiliation(s)
- Michel R Popoff
- Unité des Bactéries anaérobies et Toxines; Institut Pasteur; Paris, France
| |
Collapse
|
7
|
Tsuge H, Tsurumura T. Reaction Mechanism of Mono-ADP-Ribosyltransferase Based on Structures of the Complex of Enzyme and Substrate Protein. Curr Top Microbiol Immunol 2014; 384:69-87. [PMID: 24990621 DOI: 10.1007/82_2014_415] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mono-ADP-ribosylation is a post-translational protein modification catalyzed by bacterial toxins and exoenzymes that function as ADP-ribosyltransferases. Despite the importance of this modification, the reaction mechanism remains poorly understood due to a lack of information on the crystal structure of these enzymes in complex with a substrate protein. Recently, the structures of two such complexes became available, which shed new light on the mechanisms of mono-ADP-ribosylation. In this review, we consider the reaction mechanism based on the structures of ADP-ribosyltransferases in complex with a substrate protein.
Collapse
Affiliation(s)
- Hideaki Tsuge
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, 603-8555, Japan,
| | | |
Collapse
|
8
|
Arginine ADP-ribosylation mechanism based on structural snapshots of iota-toxin and actin complex. Proc Natl Acad Sci U S A 2013; 110:4267-72. [PMID: 23382240 DOI: 10.1073/pnas.1217227110] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Clostridium perfringens iota-toxin (Ia) mono-ADP ribosylates Arg177 of actin, leading to cytoskeletal disorganization and cell death. To fully understand the reaction mechanism of arginine-specific mono-ADP ribosyl transferase, the structure of the toxin-substrate protein complex must be characterized. Recently, we solved the crystal structure of Ia in complex with actin and the nonhydrolyzable NAD(+) analog βTAD (thiazole-4-carboxamide adenine dinucleotide); however, the structures of the NAD(+)-bound form (NAD(+)-Ia-actin) and the ADP ribosylated form [Ia-ADP ribosylated (ADPR)-actin] remain unclear. Accidentally, we found that ethylene glycol as cryo-protectant inhibits ADP ribosylation and crystallized the NAD(+)-Ia-actin complex. Here we report high-resolution structures of NAD(+)-Ia-actin and Ia-ADPR-actin obtained by soaking apo-Ia-actin crystal with NAD(+) under different conditions. The structures of NAD(+)-Ia-actin and Ia-ADPR-actin represent the pre- and postreaction states, respectively. By assigning the βTAD-Ia-actin structure to the transition state, the strain-alleviation model of ADP ribosylation, which we proposed previously, is experimentally confirmed and improved. Moreover, this reaction mechanism appears to be applicable not only to Ia but also to other ADP ribosyltransferases.
Collapse
|
9
|
Abstract
In the highly metastatic B16F10 melanoma cell line, activation of the signalling molecules that promote cell proliferation and survival on conventional adhesive culture dishes may also be responsible for the growth and resistance to anoikis of aggregates on a non-adhesive substratum. We have examined the influence of bacterial ADP-ribosyltransferases C3-like exoenzymes, which selectively modify RhoA, B and C proteins and inhibit signal pathways controlled by them. RNA interference [siRNA (small interfering RNA) Akt (also known as protein kinase B)] and a PI3K (phosphoinositide 3-kinase) inhibitor were used to analyse the changes caused by inhibiting the PI3K/Akt pathway. Inhibiting the activation of RhoA, B, C and Akt expression resulted in a decrease of the number of cells cultured in aggregates, and caspase 3 activation. RhoA activation and RhoB and RhoC expression were controlled by Akt, but not RhoA expression. Inhibiting Akt and RhoA reduced the expression of α5 integrin, and inactivated FAK (focal adhesion kinase) in B16F10 cells cultured as aggregates. Thus, inhibiting Rho subfamily proteins and Akt expression inactivates the FAK pathway and induces anoikis in anoikis-resistant cells. The activation of RhoA in melanoma cells can depend on PI3K/Akt activation, suggesting that PI3K/Akt is a suitable target for new therapeutic approaches.
Collapse
|
10
|
Deng J, Feng E, Ma S, Zhang Y, Liu X, Li H, Huang H, Zhu J, Zhu W, Shen X, Miao L, Liu H, Jiang H, Li J. Design and Synthesis of Small Molecule RhoA Inhibitors: A New Promising Therapy for Cardiovascular Diseases? J Med Chem 2011; 54:4508-22. [DOI: 10.1021/jm200161c] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jing Deng
- School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Enguang Feng
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Sheng Ma
- Department of Clinical Pharmacology Research Lab, The First Affiliated Hospital of Soochow University, 188 Shi Zhi Street, Suzhou 215006, China
| | - Yan Zhang
- Department of Clinical Pharmacology Research Lab, The First Affiliated Hospital of Soochow University, 188 Shi Zhi Street, Suzhou 215006, China
| | - Xiaofeng Liu
- School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Honglin Li
- School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Huang Huang
- School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Jin Zhu
- School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Weiliang Zhu
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Xu Shen
- School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Liyan Miao
- Department of Clinical Pharmacology Research Lab, The First Affiliated Hospital of Soochow University, 188 Shi Zhi Street, Suzhou 215006, China
| | - Hong Liu
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Hualiang Jiang
- School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Jian Li
- School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| |
Collapse
|
11
|
Abstract
Clostridia produce the highest number of toxins of any type of bacteria and are involved in severe diseases in humans and other animals. Most of the clostridial toxins are pore-forming toxins responsible for gangrenes and gastrointestinal diseases. Among them, perfringolysin has been extensively studied and it is the paradigm of the cholesterol-dependent cytolysins, whereas Clostridium perfringens epsilon-toxin and Clostridium septicum alpha-toxin, which are related to aerolysin, are the prototypes of clostridial toxins that form small pores. Other toxins active on the cell surface possess an enzymatic activity, such as phospholipase C and collagenase, and are involved in the degradation of specific cell-membrane or extracellular-matrix components. Three groups of clostridial toxins have the ability to enter cells: large clostridial glucosylating toxins, binary toxins and neurotoxins. The binary and large clostridial glucosylating toxins alter the actin cytoskeleton by enzymatically modifying the actin monomers and the regulatory proteins from the Rho family, respectively. Clostridial neurotoxins proteolyse key components of neuroexocytosis. Botulinum neurotoxins inhibit neurotransmission at neuromuscular junctions, whereas tetanus toxin targets the inhibitory interneurons of the CNS. The high potency of clostridial toxins results from their specific targets, which have an essential cellular function, and from the type of modification that they induce. In addition, clostridial toxins are useful pharmacological and biological tools.
Collapse
Affiliation(s)
- Michel R Popoff
- Institut Pasteur, Bactéries Anaérobies et Toxines, 75724 Paris cedex 15, France.
| | | |
Collapse
|