1
|
Peoples LM, Isanta-Navarro J, Bras B, Hand BK, Rosenzweig F, Elser JJ, Church MJ. Physiology, fast and slow: bacterial response to variable resource stoichiometry and dilution rate. mSystems 2024:e0077024. [PMID: 38980051 DOI: 10.1128/msystems.00770-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 06/19/2024] [Indexed: 07/10/2024] Open
Abstract
Microorganisms grow despite imbalances in the availability of nutrients and energy. The biochemical and elemental adjustments that bacteria employ to sustain growth when these resources are suboptimal are not well understood. We assessed how Pseudomonas putida KT2440 adjusts its physiology at differing dilution rates (to approximate growth rates) in response to carbon (C), nitrogen (N), and phosphorus (P) stress using chemostats. Cellular elemental and biomolecular pools were variable in response to different limiting resources at a slow dilution rate of 0.12 h-1, but these pools were more similar across treatments at a faster rate of 0.48 h-1. At slow dilution rates, limitation by P and C appeared to alter cell growth efficiencies as reflected by changes in cellular C quotas and rates of oxygen consumption, both of which were highest under P- and lowest under C- stress. Underlying these phenotypic changes was differential gene expression of terminal oxidases used for ATP generation that allows for increased energy generation efficiency. In all treatments under fast dilution rates, KT2440 formed aggregates and biofilms, a physiological response that hindered an accurate assessment of growth rate, but which could serve as a mechanism that allows cells to remain in conditions where growth is favorable. Our findings highlight the ways that microorganisms dynamically adjust their physiology under different resource supply conditions, with distinct mechanisms depending on the limiting resource at slow growth and convergence toward an aggregative phenotype with similar compositions under conditions that attempt to force fast growth. IMPORTANCE All organisms experience suboptimal growth conditions due to low nutrient and energy availability. Their ability to survive and reproduce under such conditions determines their evolutionary fitness. By imposing suboptimal resource ratios under different dilution rates on the model organism Pseudomonas putida KT2440, we show that this bacterium dynamically adjusts its elemental composition, morphology, pools of biomolecules, and levels of gene expression. By examining the ability of bacteria to respond to C:N:P imbalance, we can begin to understand how stoichiometric flexibility manifests at the cellular level and impacts the flow of energy and elements through ecosystems.
Collapse
Affiliation(s)
- Logan M Peoples
- Flathead Lake Biological Station, University of Montana, Polson, Montana, USA
| | - Jana Isanta-Navarro
- Flathead Lake Biological Station, University of Montana, Polson, Montana, USA
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Benedicta Bras
- Flathead Lake Biological Station, University of Montana, Polson, Montana, USA
| | - Brian K Hand
- Flathead Lake Biological Station, University of Montana, Polson, Montana, USA
| | - Frank Rosenzweig
- Division of Biological Sciences, University of Montana, Missoula, Montana, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - James J Elser
- Flathead Lake Biological Station, University of Montana, Polson, Montana, USA
| | - Matthew J Church
- Flathead Lake Biological Station, University of Montana, Polson, Montana, USA
| |
Collapse
|
2
|
Gao S, Zheng F, Yue L, Chen B. Chronic cadmium exposure impairs flight behavior by dampening flight muscle carbon metabolism in bumblebees. JOURNAL OF HAZARDOUS MATERIALS 2024; 466:133628. [PMID: 38301442 DOI: 10.1016/j.jhazmat.2024.133628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/03/2024]
Abstract
Cadmium pollution affects the global ecosystem because cadmium can be transferred up the food chain. The bumblebee, Bombus terrestris, is an important insect pollinator. Their foraging activity on flowers exposes them to harmful heavy metals, which damages their health and leads to massive population declines. However, the effects of chronic exposure to heavy metals on the flight performance of bumblebees have not yet been characterized. Here, we studied variation in the flight capacity of bumblebees induced by chronic cadmium exposure at field-realistic concentrations using behavioral, physiological, and molecular approaches. Chronic cadmium exposure caused a significant reduction in the duration, distance, and mean velocity of bumblebee flight. Transcriptome analysis showed that the impairment of carbon metabolism and mitochondrial dysfunction in the flight muscle were the primary causes. Physiological, biochemical, and metabolomic analyses validated disruptions in energy metabolism, and impairments in mitochondrial respiratory chain complexes activities. Histological analysis revealed muscle fiber damage and mitochondrial loss. Exogenous decanoic acid or citric acid partially restored sustained flight ability of bumblebees by mitigating muscle fiber damage and increasing energy generation. These findings provide insights into how long-term cadmium stress affects the flight ability of insects and will aid human muscle or exercise-related disease research.
Collapse
Affiliation(s)
- Shen Gao
- College of Life Sciences, Hebei University, Baoding 071002, China
| | - Fei Zheng
- College of Life Sciences, Hebei University, Baoding 071002, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Lei Yue
- College of Life Sciences, Hebei University, Baoding 071002, China
| | - Bing Chen
- College of Life Sciences, Hebei University, Baoding 071002, China.
| |
Collapse
|
3
|
Helena-Bueno K, Rybak MY, Ekemezie CL, Sullivan R, Brown CR, Dingwall C, Baslé A, Schneider C, Connolly JPR, Blaza JN, Csörgő B, Moynihan PJ, Gagnon MG, Hill CH, Melnikov SV. A new family of bacterial ribosome hibernation factors. Nature 2024; 626:1125-1132. [PMID: 38355796 PMCID: PMC10901736 DOI: 10.1038/s41586-024-07041-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 01/08/2024] [Indexed: 02/16/2024]
Abstract
To conserve energy during starvation and stress, many organisms use hibernation factor proteins to inhibit protein synthesis and protect their ribosomes from damage1,2. In bacteria, two families of hibernation factors have been described, but the low conservation of these proteins and the huge diversity of species, habitats and environmental stressors have confounded their discovery3-6. Here, by combining cryogenic electron microscopy, genetics and biochemistry, we identify Balon, a new hibernation factor in the cold-adapted bacterium Psychrobacter urativorans. We show that Balon is a distant homologue of the archaeo-eukaryotic translation factor aeRF1 and is found in 20% of representative bacteria. During cold shock or stationary phase, Balon occupies the ribosomal A site in both vacant and actively translating ribosomes in complex with EF-Tu, highlighting an unexpected role for EF-Tu in the cellular stress response. Unlike typical A-site substrates, Balon binds to ribosomes in an mRNA-independent manner, initiating a new mode of ribosome hibernation that can commence while ribosomes are still engaged in protein synthesis. Our work suggests that Balon-EF-Tu-regulated ribosome hibernation is a ubiquitous bacterial stress-response mechanism, and we demonstrate that putative Balon homologues in Mycobacteria bind to ribosomes in a similar fashion. This finding calls for a revision of the current model of ribosome hibernation inferred from common model organisms and holds numerous implications for how we understand and study ribosome hibernation.
Collapse
Affiliation(s)
| | - Mariia Yu Rybak
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | | | - Rudi Sullivan
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - Charlotte R Brown
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | | | - Arnaud Baslé
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Claudia Schneider
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | | | - James N Blaza
- Department of Chemistry, University of York, York, UK
- York Structural Biology Laboratory, University of York, York, UK
- York Biomedical Research Institute, University of York, York, UK
| | - Bálint Csörgő
- Synthetic and Systems Biology Unit, Institute of Biochemistry, HUN-REN Biological Research Centre, Szeged, Hungary
| | | | - Matthieu G Gagnon
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA.
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.
- Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA.
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX, USA.
| | - Chris H Hill
- York Structural Biology Laboratory, University of York, York, UK.
- York Biomedical Research Institute, University of York, York, UK.
- Department of Biology, University of York, York, UK.
| | - Sergey V Melnikov
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK.
| |
Collapse
|
4
|
Pourciau C, Yakhnin H, Pannuri A, Gorelik MG, Lai YJ, Romeo T, Babitzke P. CsrA coordinates the expression of ribosome hibernation and anti-σ factor proteins. mBio 2023; 14:e0258523. [PMID: 37943032 PMCID: PMC10746276 DOI: 10.1128/mbio.02585-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 10/02/2023] [Indexed: 11/10/2023] Open
Abstract
IMPORTANCE The Csr/Rsm system (carbon storage regulator or repressor of stationary phase metabolites) is a global post-transcriptional regulatory system that coordinates and responds to environmental cues and signals, facilitating the transition between active growth and stationary phase. Another key determinant of bacterial lifestyle decisions is the management of the cellular gene expression machinery. Here, we investigate the connection between these two processes in Escherichia coli. Disrupted regulation of the transcription and translation machinery impacts many cellular functions, including gene expression, growth, fitness, and stress resistance. Elucidating the role of the Csr system in controlling the activity of RNAP and ribosomes advances our understanding of mechanisms controlling bacterial growth. A more complete understanding of these processes could lead to the improvement of therapeutic strategies for recalcitrant infections.
Collapse
Affiliation(s)
- Christine Pourciau
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Helen Yakhnin
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Archanna Pannuri
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Mark G. Gorelik
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Ying-Jung Lai
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Tony Romeo
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| |
Collapse
|
5
|
Ciolli Mattioli C, Eisner K, Rosenbaum A, Wang M, Rivalta A, Amir A, Golding I, Avraham R. Physiological stress drives the emergence of a Salmonella subpopulation through ribosomal RNA regulation. Curr Biol 2023; 33:4880-4892.e14. [PMID: 37879333 PMCID: PMC10843543 DOI: 10.1016/j.cub.2023.09.064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/24/2023] [Accepted: 09/26/2023] [Indexed: 10/27/2023]
Abstract
Bacteria undergo cycles of growth and starvation to which they must adapt swiftly. One important strategy for adjusting growth rates relies on ribosomal levels. Although high ribosomal levels are required for fast growth, their dynamics during starvation remain unclear. Here, we analyzed ribosomal RNA (rRNA) content of individual Salmonella cells by using fluorescence in situ hybridization (rRNA-FISH) and measured a dramatic decrease in rRNA numbers only in a subpopulation during nutrient limitation, resulting in a bimodal distribution of cells with high and low rRNA content. During nutritional upshifts, the two subpopulations were associated with distinct phenotypes. Using a transposon screen coupled with rRNA-FISH, we identified two mutants, DksA and RNase I, acting on rRNA transcription shutdown and degradation, which abolished the formation of the subpopulation with low rRNA content. Our work identifies a bacterial mechanism for regulation of ribosomal bimodality that may be beneficial for population survival during starvation.
Collapse
Affiliation(s)
- Camilla Ciolli Mattioli
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Kfir Eisner
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Aviel Rosenbaum
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Mengyu Wang
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andre' Rivalta
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ariel Amir
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ido Golding
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Roi Avraham
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
| |
Collapse
|