Cyanobacteria possess circadian clocks consisting of KaiABC proteins and circadian rhythm must closely relate to the primary metabolism. A @entity3793 kinase, SasA, interacts with KaiC to transduce circadian signals and widely regulates transcription in @entity14221 , although the involvement of SasA in primary metabolism has not been demonstrated at metabolite levels. Here, we generated a strain overexpressing hik8 (HOX80), an ortholog of SasA in @entity324 . HOX80 grew slowly under light conditions and lost viability under continuous dark conditions. Transcript levels of genes related to sugar catabolism remained higher in HOX80 under dark conditions. Metabolomic analysis revealed that under light conditions, glycogen was undetectable in HOX80, and there were decreased levels of metabolites of sugar catabolism and increased levels of @entity1522 , compared with those in the wild-type strain. HOX80 exhibited aberrant degradation of SigE proteins after a light-to-dark transition and immunoprecipitation analysis revealed that Hik8 directly interacts with KaiC1. The results of this study demonstrate that overexpression of hik8 widely alters sugar and @entity535 metabolism, revealing the involvement of Hik8 in primary metabolism under both light and dark conditions in this cyanobacterium.

Alteration of cyanobacterial sugar and XXXX metabolism by overexpression hik8, encoding a KaiC-associated @entity3793 kinase.

@entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity3793 :: ('CHEBI:27570', 'Chemical') :: ['histidine'] @entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino acid'] @entity324 :: ('1148', 'Species') :: ['Synechocystis sp. PCC 6803'] @entity14221 :: ('1140', 'Species') :: ['Synechococcus sp. PCC 7942']
@entity535 :: (CHEBI:33704,Chemical) :: ['amino acid']
