1
|
Peterson A, Baskett C, Ratcliff WC, Burnetti A. Transforming yeast into a facultative photoheterotroph via expression of vacuolar rhodopsin. Curr Biol 2024; 34:648-654.e3. [PMID: 38218181 DOI: 10.1016/j.cub.2023.12.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 11/03/2023] [Accepted: 12/13/2023] [Indexed: 01/15/2024]
Abstract
Phototrophic metabolism, the capture of light for energy, was a pivotal biological innovation that greatly increased the total energy available to the biosphere. Chlorophyll-based photosynthesis is the most familiar phototrophic metabolism, but retinal-based microbial rhodopsins transduce nearly as much light energy as chlorophyll does,1 via a simpler mechanism, and are found in far more taxonomic groups. Although this system has apparently spread widely via horizontal gene transfer,2,3,4 little is known about how rhodopsin genes (with phylogenetic origins within prokaryotes5,6) are horizontally acquired by eukaryotic cells with complex internal membrane architectures or the conditions under which they provide a fitness advantage. To address this knowledge gap, we sought to determine whether Saccharomyces cerevisiae, a heterotrophic yeast with no known evolutionary history of phototrophy, can function as a facultative photoheterotroph after acquiring a single rhodopsin gene. We inserted a rhodopsin gene from Ustilago maydis,7 which encodes a proton pump localized to the vacuole, an organelle normally acidified via a V-type rotary ATPase, allowing the rhodopsin to supplement heterotrophic metabolism. Probes of the physiology of modified cells show that they can deacidify the cytoplasm using light energy, demonstrating the ability of rhodopsins to ameliorate the effects of starvation and quiescence. Further, we show that yeast-bearing rhodopsins gain a selective advantage when illuminated, proliferating more rapidly than their non-phototrophic ancestor or rhodopsin-bearing yeast cultured in the dark. These results underscore the ease with which rhodopsins may be horizontally transferred even in eukaryotes, providing novel biological function without first requiring evolutionary optimization.
Collapse
Affiliation(s)
- Autumn Peterson
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30309, USA; Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30309, USA
| | - Carina Baskett
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30309, USA; Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30309, USA
| | - William C Ratcliff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30309, USA; Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30309, USA.
| | - Anthony Burnetti
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30309, USA; Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30309, USA.
| |
Collapse
|
2
|
Sunda WG, Marchetti A. Proton-pumping rhodopsins promote the growth and survival of phytoplankton in a highly variable ocean. THE ISME JOURNAL 2024; 18:wrae079. [PMID: 38696358 PMCID: PMC11104272 DOI: 10.1093/ismejo/wrae079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 04/23/2024] [Accepted: 04/29/2024] [Indexed: 05/04/2024]
Affiliation(s)
- William G Sunda
- Department of Earth, Marine, and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Adrian Marchetti
- Department of Earth, Marine, and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| |
Collapse
|
3
|
Lin S. Phosphate limitation and ocean acidification co-shape phytoplankton physiology and community structure. Nat Commun 2023; 14:2699. [PMID: 37164960 PMCID: PMC10172356 DOI: 10.1038/s41467-023-38381-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 04/28/2023] [Indexed: 05/12/2023] Open
Abstract
This Comment discusses the complexity of how ocean acidification and phosphate limitation affect phytoplankton physiologies, as well as what future research is needed to address remaining crucial questions.
Collapse
Affiliation(s)
- Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA.
| |
Collapse
|
4
|
Westermann M, Hoischen C, Wöhlbrand L, Rabus R, Rhiel E. Light and prey influence the abundances of two rhodopsins in the dinoflagellate Oxyrrhis marina. PROTOPLASMA 2023; 260:529-544. [PMID: 35871098 PMCID: PMC9931815 DOI: 10.1007/s00709-022-01795-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Antisera were raised against the C-terminal amino acid sequences of the two rhodopsins ADY17806 and AEA49880 of Oxyrrhis marina. The antisera and affinity-purified antibodies thereof were used in western immunoblotting experiments of total cell protein fractions from cultures grown either in darkness or in white, red, green, or blue light. Furthermore, the rhodopsin abundances were profiled in cultures fed with yeast or the prasinophyte Pyramimonas grossii. The immunosignals of ADY17806 and AEA49880 were similar when O. marina was grown in white, green, or blue light. Signal intensities were lower under conditions of red light and lowest in darkness. Higher amounts were registered for both rhodopsins when O. marina was fed with yeast compared to P. grossii. Furthermore, total cell protein of cultures of O. marina grown under all cultivation conditions was separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, followed by tryptic in-gel digestion and mass spectrometric analysis of the 25-kDa protein bands. The rhodopsin ADY17809 was detected in all samples of the light quality experiments and in 14 of the 16 samples of the prey quality experiments. The rhodopsin ABV22427 was not detected in one sample of the light quality experiments. It was detected in 15 of the 16 samples of the prey quality experiments. Peptide fragments of the other rhodopsins were detected less often, and no clear distribution pattern was evident with respect to the applied light quality or offered prey, indicating that none of them was exclusively formed under a distinct light regime or when feeding on yeast or the prasinophyte. Fluorescence light microscopy using the affinity-purified antibodies revealed significant labeling of the cell periphery and cell internal structures, which resembled vacuoles, tiny vesicles, and rather compact structures. Immunolabeling electron microscopy strengthened these results and showed that the cytoplasmic membrane, putative lysosome membranes, membranes encircling the food vacuole, and birefringent bodies became labeled.
Collapse
Affiliation(s)
- Martin Westermann
- Electron Microscopy Center of the Jena University Hospital, Friedrich-Schiller-University Jena, Ziegelmühlenweg 1, 07743, Jena, Germany
| | - Christian Hoischen
- CF Imaging, Leibniz Institute On Aging, Fritz-Lipmann-Institute (FLI), Beutenbergstraße 11, 07745, Jena, Germany
| | - Lars Wöhlbrand
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky University Oldenburg, P.O.B. 2503, 26129, Oldenburg, Germany
| | - Ralf Rabus
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky University Oldenburg, P.O.B. 2503, 26129, Oldenburg, Germany
| | - Erhard Rhiel
- Plankton Ecology, Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky University Oldenburg, P.O.B. 2503, 26129, Oldenburg, Germany.
| |
Collapse
|
5
|
Rhiel E, Hoischen C, Westermann M. Rhodopsins build up the birefringent bodies of the dinoflagellate Oxyrrhis marina. PROTOPLASMA 2022; 259:1047-1060. [PMID: 34738175 PMCID: PMC9184458 DOI: 10.1007/s00709-021-01717-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
The ultrastructure of the birefringent bodies of the dinoflagellate Oxyrrhis marina was investigated by transmission electron microscopy. Ultrathin sectioning revealed that the bodies consist of highly ordered and densely packed lamellae, which show a regular striation along their longitudinal axis. A lattice distance of 6.1 nm was measured for the densely packed lamellae by FFT (Fast Fourier Transformation) analysis. In addition, a rather faint and oblique running striation was registered. Lamellae sectioned rather oblique or almost close to the surface show a honeycombed structure with a periodicity of 7.2-7.8 nm. Freeze-fracture transmission electron microscopy revealed that the lamellae are composed of highly ordered, crystalline arrays of particles. Here, FFT analysis resulted in lattice distances of 7.0-7.6 nm. Freeze-fracture transmission electron microscopy further revealed that the bodies remained intact after cell rupture followed by ascending flotation of the membrane fractions on discontinuous sucrose gradients. The birefringent bodies most likely are formed by evaginations of membranes, which separate the cytoplasm from the food vacuoles. Distinct, slightly reddish-colored areas, which resembled the birefringent bodies with respect to size and morphology, were registered by bright field light microscopy within Oxyrrhis marina cells. An absorbance maximum at 540 nm was registered for these areas, indicating that they are composed of rhodopsins. This was finally proven by immuno-transmission electron microscopy, as antisera directed against the C-terminal amino acid sequences of the rhodopsins AEA49880 and ADY17806 intensely immunolabeled the birefringent bodies of Oxyrrhis marina.
Collapse
Affiliation(s)
- Erhard Rhiel
- Plankton Ecology, Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky University Oldenburg, Carl-von-Ossietzky-Straße 9-11, D-26129, Oldenburg, Germany.
| | - Christian Hoischen
- CF Imaging, Leibniz Institute On Aging, Fritz-Lipmann-Institute (FLI), Beutenbergstraße 11, D-07745, Jena, Germany
| | - Martin Westermann
- Electron Microscopy Center at the Jena University Hospital, Friedrich-Schiller-University Jena, Ziegelmühlenweg 1, D-07743, Jena, Germany
| |
Collapse
|
6
|
Govorunova EG, Sineshchekov OA, Spudich JL. Emerging Diversity of Channelrhodopsins and Their Structure-Function Relationships. Front Cell Neurosci 2022; 15:800313. [PMID: 35140589 PMCID: PMC8818676 DOI: 10.3389/fncel.2021.800313] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/28/2021] [Indexed: 12/12/2022] Open
Abstract
Cation and anion channelrhodopsins (CCRs and ACRs, respectively) from phototactic algae have become widely used as genetically encoded molecular tools to control cell membrane potential with light. Recent advances in polynucleotide sequencing, especially in environmental samples, have led to identification of hundreds of channelrhodopsin homologs in many phylogenetic lineages, including non-photosynthetic protists. Only a few CCRs and ACRs have been characterized in detail, but there are indications that ion channel function has evolved within the rhodopsin superfamily by convergent routes. The diversity of channelrhodopsins provides an exceptional platform for the study of structure-function evolution in membrane proteins. Here we review the current state of channelrhodopsin research and outline perspectives for its further development.
Collapse
|
7
|
Bioluminescence and Photoreception in Unicellular Organisms: Light-Signalling in a Bio-Communication Perspective. Int J Mol Sci 2021; 22:ijms222111311. [PMID: 34768741 PMCID: PMC8582858 DOI: 10.3390/ijms222111311] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 12/13/2022] Open
Abstract
Bioluminescence, the emission of light catalysed by luciferases, has evolved in many taxa from bacteria to vertebrates and is predominant in the marine environment. It is now well established that in animals possessing a nervous system capable of integrating light stimuli, bioluminescence triggers various behavioural responses and plays a role in intra- or interspecific visual communication. The function of light emission in unicellular organisms is less clear and it is currently thought that it has evolved in an ecological framework, to be perceived by visual animals. For example, while it is thought that bioluminescence allows bacteria to be ingested by zooplankton or fish, providing them with favourable conditions for growth and dispersal, the luminous flashes emitted by dinoflagellates may have evolved as an anti-predation system against copepods. In this short review, we re-examine this paradigm in light of recent findings in microorganism photoreception, signal integration and complex behaviours. Numerous studies show that on the one hand, bacteria and protists, whether autotrophs or heterotrophs, possess a variety of photoreceptors capable of perceiving and integrating light stimuli of different wavelengths. Single-cell light-perception produces responses ranging from phototaxis to more complex behaviours. On the other hand, there is growing evidence that unicellular prokaryotes and eukaryotes can perform complex tasks ranging from habituation and decision-making to associative learning, despite lacking a nervous system. Here, we focus our analysis on two taxa, bacteria and dinoflagellates, whose bioluminescence is well studied. We propose the hypothesis that similar to visual animals, the interplay between light-emission and reception could play multiple roles in intra- and interspecific communication and participate in complex behaviour in the unicellular world.
Collapse
|