title: Stability of the Synechococcus elongatus PCC 7942 circadian clock under directed anti-phase expression of the kai genes.
abstract: The kaiA, kaiB and kaiC genes encode the core components of the cyanobacterial circadian clock in Synechococcus elongatus PCC 7942. Rhythmic expression patterns of kaiA and of the kaiBC operon normally peak in synchrony. In some mutants the relative timing of peaks (phase relationship) between these transcription units is altered, but circadian rhythms persist robustly. In this study, the importance of the transcriptional timing of kai genes was examined. Expressing either kaiA or kaiBC from a heterologous promoter whose peak expression occurs 12 h out of phase from the norm, and thus 12 h out of phase from the other kai locus, did not affect the time required for one cycle (period) or phase of the circadian rhythm, as measured by bioluminescence reporters. Furthermore, the data confirm that specific cis elements within the promoters of the kai genes are not necessary to sustain clock function.
authors.affiliation: Department of Biology, The University of St Thomas, St Paul, MN 55105, USA.
authors.forename: Jayna L
authors.initials: JL
authors.lastname: Ditty
authors.affiliation: Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX 77843-3258, USA.
authors.forename: Shannon R
authors.initials: SR
authors.lastname: Canales
authors.affiliation: Department of Biology, The University of St Thomas, St Paul, MN 55105, USA.
authors.forename: Breanne E
authors.initials: BE
authors.lastname: Anderson
authors.affiliation: Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX 77843-3258, USA.
authors.forename: Stanly B
authors.initials: SB
authors.lastname: Williams
authors.affiliation: Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX 77843-3258, USA.
authors.forename: Susan S
authors.initials: SS
authors.lastname: Golden
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001683:Biological Clocks / Q000235:genetics / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D056925:Circadian Rhythm Signaling Peptides and Proteins; D000458:Cyanobacteria / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D010766:Phosphorylation
chemical_list: D001426:Bacterial Proteins; D056925:Circadian Rhythm Signaling Peptides and Proteins; C114269:KaiA protein, cyanobacteria; C114270:KaiB protein, cyanobacteria; C114271:KaiC protein, cyanobacteria