Expression of a gene cluster kaiABC as a circadian feedback process in cyanobacteria - PubMed (original) (raw)

Expression of a gene cluster kaiABC as a circadian feedback process in cyanobacteria

M Ishiura et al. Science. 1998.

Abstract

Cyanobacteria are the simplest organisms known to have a circadian clock. A circadian clock gene cluster kaiABC was cloned from the cyanobacterium Synechococcus. Nineteen clock mutations were mapped to the three kai genes. Promoter activities upstream of the kaiA and kaiB genes showed circadian rhythms of expression, and both kaiA and kaiBC messenger RNAs displayed circadian cycling. Inactivation of any single kai gene abolished these rhythms and reduced kaiBC-promoter activity. Continuous kaiC overexpression repressed the kaiBC promoter, whereas kaiA overexpression enhanced it. Temporal kaiC overexpression reset the phase of the rhythms. Thus, a negative feedback control of kaiC expression by KaiC generates a circadian oscillation in cyanobacteria, and KaiA sustains the oscillation by enhancing kaiC expression.

PubMed Disclaimer

Comment in

• New timepiece has a familiar ring.
  Barinaga M. Barinaga M. Science. 1998 Sep 4;281(5382):1429, 1431. doi: 10.1126/science.281.5382.1429. Science. 1998. PMID: 9750109 No abstract available.

Publication types

MeSH terms

Substances

LinkOut - more resources

• Full Text Sources

  • Atypon
  • Ovid Technologies, Inc.

• Other Literature Sources

  • The Lens - Patent Citations

• Molecular Biology Databases

  • BioCyc
  • Gene Ontology