Tao Dong
@ucalgary.ca
Associate Professor, Faculty of Veterinary Medicine
University of Calgary
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Xiao-Yan Wang, Md. Mehadi Hassan, Xiao He, Guichun Hu, Yuxuan Ren, Haeun Kim, Seyyed Alireza Mirkhani, Jinguang Hu, Arindom Sen, Jun Wang,et al.
Elsevier BV
Yumin Kan, Yanjie Zhang, Wenhui Lin, and Tao Dong
American Society for Microbiology
ABSTRACT Acidovorax citrulli is a gram-negative plant pathogen that employs the type Ⅲ secretion system (T3SS) to infect cucurbit crops and cause bacterial fruit blotch. This bacterium also possesses an active type Ⅵ secretion system (T6SS) with strong antibacterial and antifungal activities. However, how plant cells respond to these two secretion systems and whether there is any cross talk between T3SS and T6SS during infection remain unknown. Here, we employ transcriptomic analysis to compare cellular responses to the T3SS and the T6SS during in planta infection and report distinctive effects on multiple pathways. The T3SS-mediated differentially expressed genes were enriched in the pathways of phenylpropanoid biosynthesis, plant-pathogen interaction, MAPK signaling pathway, and glutathione metabolism, while the T6SS uniquely affected genes were related to photosynthesis. The T6SS does not contribute to the in planta virulence of A. citrulli but is critical for the survival of the bacterium when mixed with watermelon phyllosphere bacteria. In addition, T3SS-mediated virulence is independent of the T6SS, and the inactivation of the T3SS does not affect the T6SS-mediated competition against a diverse set of bacterial pathogens that commonly contaminate edible plants or directly infect plants. A T6SS-active T3SS-null mutant (Ac av ) could inhibit the growth of Xanthomonas oryzae pv. oryzae significantly both in vitro and in vivo and also reduce symptoms of rice bacterial blight. In conclusion, our data demonstrate the T6SS in A. citrulli is nonpathogenic to the plant host and can be harnessed as a pathogen killer against plant-associated bacteria. IMPORTANCE Chemical pesticides are widely used to protect crops from various pathogens. Still, their extensive use has led to severe consequences, including drug resistance and environmental contamination. Here, we show that an engineered T6SS-active, but avirulent mutant of Acidovorax citrulli has strong inhibition capabilities against several pathogenic bacteria, demonstrating an effective strategy that is an alternative to chemical pesticides for sustainable agricultural practices.
Yuxuan Ren, Rufan Zhou, Tao G. Dong, and Qingye Lu
Royal Society of Chemistry (RSC)
A wood-inspired PPy/CA composite with vertically aligned channels was fabricated as a high-performance solar evaporator. The composite could decrease the energy demand for water evaporation and exhibited good stability in saline water.
Martina Milighetti, Yanchun Peng, Cedric Tan, Michal Mark, Gayathri Nageswaran, Suzanne Byrne, Tahel Ronel, Tom Peacock, Andreas Mayer, Aneesh Chandran,et al.
Elsevier BV
Yuxuan Ren, Rufan Zhou, Ruijie Yang, Tao G. Dong, and Qingye Lu
Wiley
Rational and sustainable utilization of resources is critical for the continuous development of this society. Solar energy, as one of the renewables, shows great potential in replacing part of the traditional energy supplies since it is clean, abundant, and easily convertible to thermal, electrical, and biological energies. Using solar energy as the green driving force, interfacial solar evaporation is a promising way for clean water production to alleviate global water shortage, taking advantage of its high evaporation efficiency (more than 80%) and strong adaptability toward various water sources and fields. In recent years, various kinds of materials with diverse designs have been synthesized and applied in interfacial solar evaporation for clean water production. Herein, recent progress in interfacial solar evaporators for clean water production is systematically reviewed, based on the photothermal conversion mechanisms of solar absorbers, including carbonous, semiconductor‐based, and plasmatic ones. Furthermore, key design factors and strategies in interfacial solar evaporators are reviewed and discussed from material and structural design point of view, such as water transport, thermal management, latent heat for water vaporization, and salt accumulation. Finally, some perspectives related to resolving existing problems in the field are given.
Li-Li Wu, Shuangquan Yan, Tong-Tong Pei, Ming-Xuan Tang, Hao Li, Xiaoye Liang, Shuyang Sun, and Tao Dong
American Chemical Society (ACS)
Xiaoye Liang, Hao-Yu Zheng, Ya-Jie Zhao, Yi-Qiu Zhang, Tong-Tong Pei, Yang Cui, Ming-Xuan Tang, Ping Xu, and Tao Dong
American Society for Microbiology
Gram-negative bacteria often encode multiple paralogs of the cone-shaped PAAR that sits atop the VgrG-spike and is thought to sharpen the spear-like T6SS puncturing device. However, it is unclear why PAAR is required for the assembly of some but not all T6SSs and why there are multiple PAARs if they are not required.
Ming-Xuan Tang, Sherina Dyrma, and Tao Dong
Elsevier
Anmin Ren, Minlu Jia, Jihong Liu, Tian Zhou, Liwen Wu, Tao Dong, Zhao Cai, Jiuxin Qu, Yang Liu, Liang Yang,et al.
American Society for Microbiology
Pseudomonas aeruginosa is one predominant pathogen that causes hospital-acquired infections and is one of the commonest coinfecting bacteria in immunocompromised patients and chronic wounds. This bacterium harbors a diverse accessory genome with a high frequency of gene recombination, rendering its population highly heterogeneous.
Ming Liu, Meng-Yu Zhao, Heng Wang, Zeng-Hang Wang, Zhao Wang, Ying Liu, Yin-Peng Li, Tao Dong, and Yang Fu
American Society for Microbiology
The type VI secretion system used by a broad range of Gram-negative bacteria delivers toxic proteins to target adjacent eukaryotic and prokaryotic cells. Diversification of effector proteins determines the complex bacterium-bacterium interactions and impacts the health of hosts and environmental ecosystems in which bacteria reside.
Xiao He, Haeun Kim, Tao G. Dong, Ian Gates, and Qingye Lu
Springer Science and Business Media LLC
Yang Cui, Tong-Tong Pei, Xiaoye Liang, Hao Li, Hao-Yu Zheng, and Tao Dong
American Society for Microbiology
The T6SS is a powerful and versatile protein delivery system. However, the complexity of its macromolecular structure and gene regulation makes it not a trivial task to reconstitute the T6SSs of pathogens in a nonpathogenic host.
Kevin Manera, Fatima Kamal, Brianne Burkinshaw, and Tao G. Dong
Wiley
Equipped with a plethora of secreted toxic effectors, protein secretion systems are essential for bacteria to interact with and manipulate their neighboring environment to survive in host microbiota and other highly competitive communities. While effectors have received spotlight attention in secretion system studies, many require accessory chaperone and adaptor proteins for proper folding/unfolding and stability throughout the secretion process. Here we review the functions of chaperones and adaptors of three protein secretions systems, T3SS, T4SS, and T6SS, which are employed by many Gram-negative bacterial pathogens to deliver toxins to bacterial, plant, and mammalian host cells through direct contact. Since chaperone and adaptor functions of the T3SS and the T4SS are relatively well studied, we discuss in detail the methods of chaperone-facilitated effector secretion by the T6SS and highlight commonalities between the effector chaperone/adaptor proteins of these diverse secretion systems. While the chaperones and adaptors are generally referred to as accessory proteins as they are not directly involved in toxicities to target cells, they are nonetheless vital for the biological functions of the secretion systems. Future research on biochemical and structural properties of these chaperones will not only elucidate the mechanisms of chaperon-effector binding and release process but also facilitate custom design of cargo effectors to be translocated by these widespread secretion systems for biotechnological applications.
Ming-Xuan Tang, Tong-Tong Pei, Qi Xiang, Zeng-Hang Wang, Han Luo, Xing-Yu Wang, Yang Fu, and Tao Dong
Springer Science and Business Media LLC
Tong‐Tong Pei, Yumin Kan, Zeng‐Hang Wang, Ming‐Xuan Tang, Hao Li, Shuangquan Yan, Yang Cui, Hao‐Yu Zheng, Han Luo, Xiaoye Liang,et al.
Wiley
Yuxuan Ren, Steven J. Hersch, Xiao He, Rufan Zhou, Tao G. Dong, and Qingye Lu
Elsevier BV
Haeun Kim, Brianne J. Burkinshaw, Linh G. Lam, Kevin Manera, and Tao G. Dong
American Society for Microbiology
Cholera is a serious infectious disease in tropical regions causing millions of infections annually. Vibrio cholerae , the causative agent of cholera, has gained multi-antibiotic resistance over the years, posing greater threat to public health and current treatment strategies. Here we report two compounds that effectively target the growth of V. cholerae and have the potential to control cholera infection.
Hao-Yu Zheng, Liang Yang, and Tao Dong
American Society for Microbiology
The type VI secretion system (T6SS) belongs to the evolutionarily related group of contractile injection systems that employ a contractile outer sheath to inject a rigid spear-like inner tube into target bacterial and eukaryotic cells. The tip of the rigid tube is often decorated by a PAAR-repeat protein as a key structural component.
Xiaoye Liang, Tong-Tong Pei, Hao Li, Hao-Yu Zheng, Han Luo, Yang Cui, Ming-Xuan Tang, Ya-Jie Zhao, Ping Xu, and Tao Dong
Public Library of Science (PLoS)
The type VI secretion system (T6SS) is a spear-like nanomachine found in gram-negative pathogens for delivery of toxic effectors to neighboring bacterial and host cells. Its assembly requires a tip spike complex consisting of a VgrG-trimer, a PAAR protein, and the interacting effectors. However, how the spike controls T6SS assembly remains elusive. Here we investigated the role of three VgrG-effector pairs in Aeromonas dhakensis strain SSU, a clinical isolate with a constitutively active T6SS. By swapping VgrG tail sequences, we demonstrate that the C-terminal ~30 amino-acid tail dictates effector specificity. Double deletion of vgrG1&2 genes (VgrG3+) abolished T6SS secretion, which can be rescued by ectopically expressing chimeric VgrG3 with a VgrG1/2-tail but not the wild type VgrG3. In addition, deletion of effector-specific chaperones also severely impaired T6SS secretion, despite the presence of intact VgrG and effector proteins, in both SSU and Vibrio cholerae V52. We further show that SSU could deliver a V. cholerae effector VasX when expressing a plasmid-borne chimeric VgrG with VasX-specific VgrG tail and chaperone sequences. Pull-down analyses show that two SSU effectors, TseP and TseC, could interact with their cognate VgrGs, the baseplate protein TssK, and the key assembly chaperone TssA. Effectors TseL and VasX could interact with TssF, TssK and TssA in V. cholerae. Collectively, we demonstrate that chimeric VgrG-effector pairs could bypass the requirement of heterologous VgrG complex and propose that effector-stuffing inside the baseplate complex, facilitated by chaperones and the interaction with structural proteins, serves as a crucial structural determinant for T6SS assembly.
Li Song, Junfeng Pan, Yantao Yang, Zhenxing Zhang, Rui Cui, Shuangkai Jia, Zhuo Wang, Changxing Yang, Lei Xu, Tao G. Dong,et al.
Springer Science and Business Media LLC
AbstractBacterial type VI secretion systems (T6SSs) inject toxic effectors into adjacent eukaryotic and prokaryotic cells. It is generally thought that this process requires physical contact between the two cells. Here, we provide evidence of contact-independent killing by a T6SS-secreted effector. We show that the pathogen Yersinia pseudotuberculosis uses a T6SS (T6SS-3) to secrete a nuclease effector that kills other bacteria in vitro and facilitates gut colonization in mice. The effector (Tce1) is a small protein that acts as a Ca2+- and Mg2+-dependent DNase, and its toxicity is inhibited by a cognate immunity protein, Tci1. As expected, T6SS-3 mediates canonical, contact-dependent killing by directly injecting Tce1 into adjacent cells. In addition, T6SS-3 also mediates killing of neighboring cells in the absence of cell-to-cell contact, by secreting Tce1 into the extracellular milieu. Efficient contact-independent entry of Tce1 into target cells requires proteins OmpF and BtuB in the outer membrane of target cells. The discovery of a contact-independent, long-range T6SS toxin delivery provides a new perspective for understanding the physiological roles of T6SS in competition. However, the mechanisms mediating contact-independent uptake of Tce1 by target cells remain unclear.
Steven J. Hersch, Linh Lam, and Tao G. Dong
American Society for Microbiology
Delivery of protein-based drugs, antigens, and gene-editing agents has broad applications. The type VI protein secretion system (T6SS) can target both bacteria and eukaryotic cells and deliver proteins of diverse size and function.
Kevin Manera, Florence Caro, Hao Li, Tong-Tong Pei, Steven J. Hersch, John J. Mekalanos, and Tao G. Dong
Proceedings of the National Academy of Sciences
The type 6 secretion system (T6SS) is a bacterial weapon broadly distributed in gram-negative bacteria and used to kill competitors and predators. Featuring a long and double-tubular structure, this molecular machine is energetically costly to produce and thus is likely subject to diverse regulation strategies that are largely ill defined. In this study, we report a quantity-sensing control of the T6SS that down-regulates the expression of secreted components when they accumulate in the cytosol due to T6SS inactivation. Using Vibrio cholerae strains that constitutively express an active T6SS, we demonstrate that mRNA levels of secreted components, including the inner-tube protein component Hcp, were down-regulated in T6SS structural gene mutants while expression of the main structural genes remained unchanged. Deletion of both hcp gene copies restored expression from their promoters, while Hcp overexpression negatively impacted expression. We show that Hcp directly interacts with the RpoN-dependent T6SS regulator VasH, and deleting the N-terminal regulator domain of VasH abolishes this interaction as well as the expression difference of hcp operons between T6SS-active and inactive strains. We find that negative regulation of hcp also occurs in other V. cholerae strains and the pathogens Aeromonas dhakensis and Pseudomonas aeruginosa. This Hcp-dependent sensing control is likely an important energy-conserving mechanism that enables T6SS-encoding organisms to quickly adjust T6SS expression and prevent wasteful build-up of its major secreted components in the absence of their efficient export out of the bacterial cell.
Xiaoye Liang, Tong-Tong Pei, Zeng-Hang Wang, Weiliang Xiong, Li-Li Wu, Ping Xu, Shuangjun Lin, and Tao G. Dong
American Society for Microbiology
Delivery of cargo proteins via protein secretion systems has been shown as a promising tool in various applications. However, secretion systems are often used by pathogens to cause disease.
Maria Silvina Stietz, Xiaoye Liang, Hao Li, Xinran Zhang, and Tao G. Dong
Springer Science and Business Media LLC
AbstractThe type VI protein secretion system (T6SS) is a powerful needle-like machinery found in Gram-negative bacteria that can penetrate the cytosol of receiving cells in milliseconds by physical force. Anchored by its membrane-spanning complex (MC) and a baseplate (BP), the T6SS sheath-tube is assembled in a stepwise process primed by TssA and terminated by TagA. However, the molecular details of its assembly remain elusive. Here, we systematically examined the initiation and termination of contractile and non-contractile T6SS sheaths in MC-BP, tssA and tagA mutants by fluorescence microscopy. We observe long pole-to-pole sheath-tube structures in the non-contractile MC-BP defective mutants but not in the Hcp tube or VgrG spike mutants. Combining overexpression and genetic mutation data, we demonstrate complex effects of TssM, TssA and TagA interactions on T6SS sheath-tube dynamics. We also report promiscuous interactions of TagA with multiple T6SS components, similar to TssA. Our results demonstrate that priming of the T6SS sheath-tube assembly is not dependent on TssA, nor is the assembly termination dependent on the distal end TssA–TagA interaction, and highlight the tripartite control of TssA–TssM–TagA on sheath-tube initiation and termination.
Tong-Tong Pei, Hao Li, Xiaoye Liang, Zeng-Hang Wang, Guangfeng Liu, Li-Li Wu, Haeun Kim, Zhiping Xie, Ming Yu, Shuangjun Lin,et al.
Springer Science and Business Media LLC
An amendment to this paper has been published and can be accessed via a link at the top of the paper.