ArticlePLoS genetics2016
Evolution of KaiC-Dependent Timekeepers: A Proto-circadian Timing Mechanism Confers Adaptive Fitness in the Purple Bacterium Rhodopseudomonas palustris.
Article in PLoS genetics, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 35 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
35 citing papers in PubMed, 73 citations in OpenAlex.
- Time matters: circadian genetics and the molecular logic of human health and disease.Nature reviews. Genetics · 2026Review
- Could photoperiodic responses have evolved before the emergence of circadian clocks?The New phytologist · 2025Review
- Circadian Biology in Parasites: Beyond Known Mechanisms.Annual review of microbiology · 2025Review
- Composition and rhythmic variations in the microbiome of Southwestern Atlantic corals.Environmental microbiome · 2025Article
- Evolutionary origins of self-sustained Kai protein circadian oscillators in cyanobacteria.Nature communications · 2025Article
- Photomorphogenesis of Myxococcus macrosporus: new insights for light-regulation of cell development.Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology · 2024Article
- Two KaiABC systems control circadian oscillations in one cyanobacterium.Nature communications · 2024Article
- Timely symbiosis: circadian control of legume-rhizobia symbiosis.Biochemical Society transactions · 2024Review
- Endogenous clock-mediated regulation of intracellular oxygen dynamics is essential for diazotrophic growth of unicellular cyanobacteria.Nature communications · 2024Article
- Studying the Human Microbiota: Advances in Understanding the Fundamentals, Origin, and Evolution of Biological Timekeeping.International journal of molecular sciences · 2023Review
- The Hypothesis of a "Living Pulse" in Cells.Life (Basel, Switzerland) · 2023Article
- Microbial circadian clocks: host-microbe interplay in diel cycles.BMC microbiology · 2023Review
- Circadian entrainment of in vitro reactions, in real time, and around the clock.Proceedings of the National Academy of Sciences of the United States of America · 2023Article
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- From primordial clocks to circadian oscillators.Nature · 2023Article
- The effect of diurnal light cycles on biohydrogen production in a thermosiphon photobioreactor.AMB Express · 2023Article
- Perfecting the Life Clock: The Journey from PTO to TTFL.International journal of molecular sciences · 2023Review
- Insight into the metabolic potential and ecological function of a novel MagnetotacticFrontiers in microbiology · 2023Article
- Evolution of self-sustained circadian rhythms is facilitated by seasonal change of daylight.Proceedings. Biological sciences · 2022Article
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Authors and funding
5 authors at 2 institutions in 1 country.
Funding
Abstract
Circadian (daily) rhythms are a fundamental and ubiquitous property of eukaryotic organisms. However, cyanobacteria are the only prokaryotic group for which bona fide circadian properties have been persuasively documented, even though homologs of the cyanobacterial kaiABC central clock genes are distributed widely among Eubacteria and Archaea. We report the purple non-sulfur bacterium Rhodopseudomonas palustris (that harbors homologs of kaiB and kaiC) only poorly sustains rhythmicity in constant conditions-a defining characteristic of circadian rhythms. Moreover, the biochemical characteristics of the Rhodopseudomonas homolog of the KaiC protein in vivo and in vitro are different from those of cyanobacterial KaiC. Nevertheless, R. palustris cells exhibit adaptive kaiC-dependent growth enhancement in 24-h cyclic environments, but not under non-natural constant conditions. Therefore, our data indicate that Rhodopseudomonas does not have a classical circadian rhythm, but a novel timekeeping mechanism that does not sustain itself in constant conditions. These results question the adaptive value of self-sustained oscillatory capability for daily timekeepers and establish new criteria for circadian-like systems that are based on adaptive properties (i.e., fitness enhancement in rhythmic environments), rather than upon observations of persisting rhythms in constant conditions. We propose that the Rhodopseudomonas system is a "proto" circadian timekeeper, as in an ancestral system that is based on KaiC and KaiB proteins and includes some, but not necessarily all, of the canonical properties of circadian clocks. These data indicate reasonable intermediate steps by which bona fide circadian systems evolved in simple organisms.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.