Origin and evolution of circadian clock genes in prokaryotes

Proc Natl Acad Sci U S A. 2003 Mar 4;100(5):2495-500. doi: 10.1073/pnas.0130099100. Epub 2003 Feb 25.

Abstract

Regulation of physiological functions with approximate daily periodicity, or circadian rhythms, is a characteristic feature of eukaryotes. Until recently, cyanobacteria were the only prokaryotes reported to possess circadian rhythmicity. It is controlled by a cluster of three genes: kaiA, kaiB, and kaiC. Using sequence data of approximately 70 complete prokaryotic genomes from the various public depositories, we show here that the kai genes and their homologs have quite a different evolutionary history and occur in Archaea and Proteobacteria as well. Among the three genes, kaiC is evolutionarily the oldest, and kaiA is the youngest and likely evolved only in cyanobacteria. Our data suggest that the prokaryotic circadian pacemakers have evolved in parallel with the geological history of the earth, and that natural selection, multiple lateral transfers, and gene duplications and losses have been the major factors shaping their evolution.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Bacterial Proteins / physiology
  • Biological Clocks / genetics
  • Biological Clocks / physiology
  • Circadian Rhythm Signaling Peptides and Proteins
  • Circadian Rhythm* / genetics
  • Circadian Rhythm* / physiology
  • Cyanobacteria / genetics
  • Cyanobacteria / physiology*
  • Evolution, Molecular*
  • Gene Expression Regulation, Bacterial
  • Phylogeny
  • Polymorphism, Genetic
  • Time Factors

Substances

  • Bacterial Proteins
  • Circadian Rhythm Signaling Peptides and Proteins
  • KaiA protein, cyanobacteria
  • KaiB protein, cyanobacteria
  • KaiC protein, cyanobacteria