The pathway for perception and transduction of low-temperature signals in Synechocystis

Low temperature is an important environmental factor that has effects on al l living organisms. Various low-temperature-inducible genes encode products that are essential for acclimation to low temperature, but low-temperature sensors and signal transducers have not been identified. However, systemat ic disruption of putative genes for histidine kinases and random mutagenesi s of almost all the genes in the genome of the cyanobacterium Synechocystis sp. PCC 6803 have allowed us to identify two histidine kinases and a respo nse regulator as components of the pathway for perception and transduction of low-temperature signals. Inactivation, by targeted mutagenesis, of the g ene for each of the two histidine kinases and inactivation of the gene for the response regulator depressed the transcription of several low-temperatu re-inducible genes.