Stability of the Synechococcus elongatus PCC 7942 circadian clock under directed anti-phase expression of the kai genes

Microbiology ◽  
2005 ◽  
Vol 151 (8) ◽  
pp. 2605-2613 ◽  
Author(s):  
Jayna L. Ditty ◽  
Shannon R. Canales ◽  
Breanne E. Anderson ◽  
Stanly B. Williams ◽  
Susan S. Golden
Keyword(s):  
Circadian Clock ◽  
Expression Patterns ◽  
Phase Relationship ◽  
Synechococcus Elongatus ◽  
Cycle Period ◽  
Rhythmic Expression ◽  
Core Components ◽  
Synechococcus Elongatus Pcc 7942 ◽  
Time Required ◽  
Pcc 7942

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.

scholarly journals Role of KaiC phosphorylation in the circadian clock system of Synechococcus elongatus PCC 7942

2004 ◽  
Vol 101 (38) ◽  
pp. 13927-13932 ◽  
Author(s):  
T. Nishiwaki ◽  
Y. Satomi ◽  
M. Nakajima ◽  
C. Lee ◽  
R. Kiyohara ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Synechococcus Elongatus ◽  
Clock System ◽  
Synechococcus Elongatus Pcc 7942 ◽  
Pcc 7942

scholarly journals Photophysiological and Photosynthetic Complex Changes during Iron Starvation in Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e59861 ◽  
Author(s):  
Jared M. Fraser ◽  
Sarah E. Tulk ◽  
Jennifer A. Jeans ◽  
Douglas A. Campbell ◽  
Thomas S. Bibby ◽  
...  
Keyword(s):  
Synechococcus Elongatus ◽  
Iron Starvation ◽  
Synechococcus Elongatus Pcc 7942 ◽  
Pcc 7942 ◽  
Synechocystis Sp ◽  
Pcc 6803

scholarly journals Putative extracellular α-class carbonic anhydrase, EcaA, of Synechococcus elongatus PCC 7942 is an active enzyme: a sequel to an old story

Microbiology ◽  
2018 ◽  
Vol 164 (4) ◽  
pp. 576-586 ◽  
Author(s):  
Elena V. Kupriyanova ◽  
Maria A. Sinetova ◽  
Vladimir S. Bedbenov ◽  
Natalia A. Pronina ◽  
Dmitry A. Los
Keyword(s):  
Carbonic Anhydrase ◽  
Synechococcus Elongatus ◽  
Active Enzyme ◽  
Synechococcus Elongatus Pcc 7942 ◽  
Pcc 7942

Complete Replacement of the Galactolipid Biosynthesis Pathway with a Plant-Type Pathway in the Cyanobacterium Synechococcus elongatus PCC 7942

2020 ◽  
Vol 61 (9) ◽  
pp. 1661-1668
Author(s):  
Egi Tritya Apdila ◽  
Shukumi Inoue ◽  
Mie Shimojima ◽  
Koichiro Awai
Keyword(s):  
Chlorophyll Content ◽  
Membrane Lipids ◽  
Thylakoid Membranes ◽  
Synechococcus Elongatus ◽  
Biosynthesis Pathway ◽  
Plant Type ◽  
Complete Replacement ◽  
Essential Components ◽  
Synechococcus Elongatus Pcc 7942 ◽  
Pcc 7942

Abstract Monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) are the major components of thylakoid membranes and well-conserved from cyanobacteria to chloroplasts. However, cyanobacteria and chloroplasts synthesize these galactolipids using different pathways and enzymes, but they are believed to share a common ancestor. This fact implies that there was a replacement of the cyanobacterial galactolipid biosynthesis pathway during the evolution of a chloroplast. In this study, we first replaced the cyanobacterial MGDG biosynthesis pathway in a model cyanobacterium, Synechococcus elongatus PCC 7942, with the corresponding plant-type pathway. No obvious phenotype was observed under the optimum growth condition, and the content of membrane lipids was not largely altered in the transformants. We next replaced the cyanobacterial DGDG biosynthesis pathway with the corresponding plant-type pathway using the strain described above and isolated the strain harboring the replaced plant-type pathway instead of the whole galactolipid biosynthesis pathway. This transformant, SeGPT, can grow photoautotrophically, indicating that cyanobacterial galactolipid biosynthesis pathways can be functionally complemented by the corresponding plant-type pathways and that the lipid products MGDG and DGDG, and not biosynthesis pathways, are important. While SeGPT does not show strong growth retardation, the strain has low cellular chlorophyll content but it retained a similar oxygen evolution rate per chlorophyll content compared with the wild type. An increase in total membrane lipid content was observed in SeGPT, which was caused by a significant increase in DGDG content. SeGPT accumulated carotenoids from the xanthophyll groups. These results suggest that cyanobacteria have the capacity to accept other pathways to synthesize essential components of thylakoid membranes.

scholarly journals Synechocystis KaiC3 Displays Temperature- and KaiB-Dependent ATPase Activity and Is Important for Growth in Darkness

2019 ◽  
Vol 202 (4) ◽  
Author(s):  
Anika Wiegard ◽  
Christin Köbler ◽  
Katsuaki Oyama ◽  
Anja K. Dörrich ◽  
Chihiro Azai ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Circadian Clock ◽  
Atp Hydrolysis ◽  
Synechococcus Elongatus ◽  
Constant Darkness ◽  
Content Type ◽  
Clock Proteins ◽  
Pcc 7942 ◽  
Pcc 6803

ABSTRACT Cyanobacteria form a heterogeneous bacterial group with diverse lifestyles, acclimation strategies, and differences in the presence of circadian clock proteins. In Synechococcus elongatus PCC 7942, a unique posttranslational KaiABC oscillator drives circadian rhythms. ATPase activity of KaiC correlates with the period of the clock and mediates temperature compensation. Synechocystis sp. strain PCC 6803 expresses additional Kai proteins, of which KaiB3 and KaiC3 proteins were suggested to fine-tune the standard KaiAB1C1 oscillator. In the present study, we therefore characterized the enzymatic activity of KaiC3 as a representative of nonstandard KaiC homologs in vitro. KaiC3 displayed ATPase activity lower than that of the Synechococcus elongatus PCC 7942 KaiC protein. ATP hydrolysis was temperature dependent. Hence, KaiC3 is missing a defining feature of the model cyanobacterial circadian oscillator. Yeast two-hybrid analysis showed that KaiC3 interacts with KaiB3, KaiC1, and KaiB1. Further, KaiB3 and KaiB1 reduced in vitro ATP hydrolysis by KaiC3. Spot assays showed that chemoheterotrophic growth in constant darkness is completely abolished after deletion of ΔkaiAB1C1 and reduced in the absence of kaiC3. We therefore suggest a role for adaptation to darkness for KaiC3 as well as a cross talk between the KaiC1- and KaiC3-based systems. IMPORTANCE The circadian clock influences the cyanobacterial metabolism, and deeper understanding of its regulation will be important for metabolic optimizations in the context of industrial applications. Due to the heterogeneity of cyanobacteria, characterization of clock systems in organisms apart from the circadian model Synechococcus elongatus PCC 7942 is required. Synechocystis sp. strain PCC 6803 represents a major cyanobacterial model organism and harbors phylogenetically diverged homologs of the clock proteins, which are present in various other noncyanobacterial prokaryotes. By our in vitro studies we unravel the interplay of the multiple Synechocystis Kai proteins and characterize enzymatic activities of the nonstandard clock homolog KaiC3. We show that the deletion of kaiC3 affects growth in constant darkness, suggesting its involvement in the regulation of nonphotosynthetic metabolic pathways.

Sign in / Sign up

Export Citation Format

Share Document