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Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
A bacterial proteorhodopsin proton pump in marine eukaryotes.
Claudio H Slamovits1, Noriko Okamoto, Lena Burri
1Canadian Institute for Advanced Research, Botany Department, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
Nature Communications
|February 10, 2011
Summary
Marine dinoflagellates have acquired proteorhodopsins, a light-driven proton pump, through horizontal gene transfer from bacteria. This discovery reveals an alternative pathway for harnessing solar energy in eukaryotes, beyond traditional photosystems.
Area of Science:
- Microbiology
- Marine Biology
- Genetics
Background:
- Proteorhodopsins are light-driven proton pumps found in marine bacteria.
- They are widespread in prokaryotes due to lateral gene transfer but absent in eukaryotes.
- Their presence in eukaryotes was previously unknown.
Purpose of the Study:
- To investigate the presence and origin of proteorhodopsins in eukaryotic organisms.
- To understand the evolutionary history and functional implications of proteorhodopsin acquisition in protists.
Main Methods:
- Bioinformatic analysis to identify proteorhodopsin genes in dinoflagellate genomes.
- Phylogenetic analysis to determine the evolutionary origins.
- Gene expression analysis and protein localization studies in Oxyrrhis marina.
Main Results:
- Proteorhodopsins have been independently acquired at least twice in dinoflagellate protists via horizontal gene transfer from bacteria.
- In Oxyrrhis marina, proteorhodopsin is a highly expressed nuclear gene.
- The proteorhodopsin product localizes to cytoplasmic structures within the endomembrane system.
Conclusions:
- Dinoflagellates utilize proteorhodopsins as an alternative mechanism for light energy transduction.
- This finding expands our understanding of solar energy utilization in eukaryotes.
- It suggests some zooplankton may harness light for biological functions using this bacterial-derived pathway.
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