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Published on: October 11, 2022
Moonlighting in Rickettsiales: Expanding Virulence Landscape
Ana Luísa Matos1, Pedro Curto1, Isaura Simões1,2
1CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.
Abstract:
The order Rickettsiales includes species that cause a range of human diseases such as human granulocytic anaplasmosis (Anaplasma phagocytophilum), human monocytic ehrlichiosis (Ehrlichia chaffeensis), scrub typhus (Orientia tsutsugamushi), epidemic typhus (Rickettsia prowazekii), murine typhus (R. typhi), Mediterranean spotted fever (R. conorii), or Rocky Mountain spotted fever (R. rickettsii). These diseases are gaining a new momentum given their resurgence patterns and geographical expansion due to the overall rise in temperature and other human-induced pressure, thereby remaining a major public health concern. As obligate intracellular bacteria, Rickettsiales are characterized by their small genome sizes due to reductive evolution. Many pathogens employ moonlighting/multitasking proteins as virulence factors to interfere with multiple cellular processes, in different compartments, at different times during infection, augmenting their virulence. The utilization of this multitasking phenomenon by Rickettsiales as a strategy to maximize the use of their reduced protein repertoire is an emerging theme. Here, we provide an overview of the role of various moonlighting proteins in the pathogenicity of these species. Despite the challenges that lie ahead to determine the multiple potential faces of every single protein in Rickettsiales, the available examples anticipate this multifunctionality as an essential and intrinsic feature of these obligates and should be integrated into available moonlighting repositories.
Insights
Rickettsiales bacteria, responsible for diseases like typhus and RMSF, utilize multitasking proteins to enhance virulence. These moonlighting proteins are crucial for their pathogenicity and survival strategies.
Area of Science:
- Microbiology
- Pathogen Biology
- Molecular Biology
Background:
- The order Rickettsiales comprises obligate intracellular bacteria causing significant human diseases, including typhus and spotted fevers.
- These pathogens are experiencing resurgence and geographical expansion, posing a growing public health concern.
- Rickettsiales possess small genomes due to reductive evolution, necessitating efficient molecular strategies for survival and virulence.
Purpose of the Study:
- To provide an overview of the role of moonlighting proteins in the pathogenicity of Rickettsiales species.
- To highlight the significance of protein multifunctionality in maximizing virulence with a limited protein repertoire.
- To emphasize the need for integrating Rickettsiales moonlighting proteins into existing databases.
Main Methods:
- Literature review and synthesis of existing research on Rickettsiales and moonlighting proteins.
- Analysis of documented examples of moonlighting proteins in various Rickettsiales species.
- Discussion of the implications of protein moonlighting in bacterial pathogenesis.
Main Results:
- Rickettsiales pathogens extensively utilize moonlighting proteins as virulence factors.
- These multitasking proteins interfere with multiple host cellular processes, enhancing pathogenicity.
- Protein moonlighting is an essential strategy for Rickettsiales to maximize the utility of their reduced proteome.
Conclusions:
- Moonlighting proteins are critical for the virulence and pathogenicity of Rickettsiales.
- The multifunctionality of these proteins is an intrinsic feature enabling survival and infection.
- Further research is needed to fully elucidate the roles of these proteins and integrate findings into scientific repositories.
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