Szlak sygnalizacyjny cAMP u sinic
1. Wstęp. 2. Szlaki sygnalizacyjne cyklicznych nukleotydów u sinic. 2.1. cAMP w komórkach sinic. 2.2. Synteza cAMP u sinic. 2.3. Hydroliza cAMP u sinic. 2.4. Szlak sygnalizacyjny cGMP u sinic. 3. Biologiczna rola cAMP u sinic. 3.1. Rola szlaku cAMP w reakcji na czynniki środowiskowe i w regulacji wzrostu komórek sinic. 3.2. Regulacja transkrypcji przez szlak sygnalizacyjny cAMP u sinic.
Abstract: cAMP signaling pathway is a common functional pathway of signal transduction in Prokaryota and in Eukaryota. Participation of cAMP signaling pathway in the regulation of metabolic processes in cyanobacteria cells has been demonstrated by the studies showing a distinct response of these organisms to exogenous cAMP in the medium. cAMP was detected in cyanobacteria cells with changes in its level dependenting on environmental factors. In these organisms the presence of cAMP synthesis and degradation enzymes (AC and PDE, respectively) was demonstrated and genes encoding proteins involved in signal transduction pathway of cAMP were identified. Currently the sequences of 29 complete genomes of different species of cyanobacteria (and their strains) are known in which different genes connected with cAMP pathway have been identified. There include the genes ecoding AC and PDE cAMP acceptors (CRP), which are transcription factors activated by this nucleotide and genes encoding proteins playing an important role in different physiological processes whose promoters have the CRP binding sequence. These genes encode proteins involved in photosynthesis, carbon metabolism and nitrogen assimilation as well as transporter and porin proteins, protein kinases and transcription factors etc. Current studies of cAMP signaling pathway in cyanobacteria may indicate that it is not a universal pathway regulating cell functioning in the genomes of some cyanobacteria AC, PDE, CRP genes and genes whose activity is regulated by CRP were not detected. However, there is a possibility that their genomes may contain modified, not yet identified sequences encoding individual elements of the cAMP pathway.
1. Introduction. 2. Cyclic nucleotide signaling pathways in cyanobacteria. 2.1. cAMP in cyanobacteria. 2.2. cAMP synthesis in cyanobacteria. 2.3. cAMP hydrolysis in cyanobacteria. 2.4. cGMP signaling pathway in cyanobacteria. 3. Biological role of cAMP in cyanobacteria. 3.1. Role of cAMP pathway in the reaction to environmental factors and in the regulation of cell growth of cyanobacteria. 3.2. Regulation of transcription in cyanobacteria by cAMP signaling pathway. 4. Summary