A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Impact of Different Group 2 Sigma Factors on Light Use Efficiency and High Salt Stress in the Cyanobacterium Synechocystis sp PCC 6803
Tekijät: Tyystjärvi T, Huokko T, Rantamäki S, Tyystjärvi E
Kustantaja: PUBLIC LIBRARY SCIENCE
Julkaisuvuosi: 2013
Journal: PLoS ONE
Tietokannassa oleva lehden nimi: PLOS ONE
Lehden akronyymi: PLOS ONE
Numero sarjassa: 4
Vuosikerta: 8
Numero: 4
Sivujen määrä: 8
ISSN: 1932-6203
DOI: https://doi.org/10.1371/journal.pone.0063020
Tiivistelmä
Sigma factors of RNA polymerase recognize promoters and have a central role in controlling transcription initiation and acclimation to changing environmental conditions. The cyanobacterium Synechocystis sp. PCC 6803 encodes four non-essential group 2 sigma factors, SigB, SigC, SigD and SigE that closely resemble the essential SigA factor. Three out of four group 2 sigma factors were simultaneously inactivated and acclimation responses of the triple inactivation strains were studied. All triple inactivation strains grew slowly in low light, and our analysis suggests that the reason is a reduced capacity to adjust the perception of light. Simultaneous inactivation of SigB and SigD hampered growth also in high light. SigB is the most important group 2 sigma factor for salt acclimation, and elimination of all the other group 2 sigma factors slightly improved the salt tolerance of Synechocystis. Presence of only SigE allowed full salt acclimation including up-regulation of hspA and ggpS genes, but more slowly than SigB. Cells with only SigD acclimated to high salt but the acclimation processes differed from those of the control strain. Presence of only SigC prevented salt acclimation.
Sigma factors of RNA polymerase recognize promoters and have a central role in controlling transcription initiation and acclimation to changing environmental conditions. The cyanobacterium Synechocystis sp. PCC 6803 encodes four non-essential group 2 sigma factors, SigB, SigC, SigD and SigE that closely resemble the essential SigA factor. Three out of four group 2 sigma factors were simultaneously inactivated and acclimation responses of the triple inactivation strains were studied. All triple inactivation strains grew slowly in low light, and our analysis suggests that the reason is a reduced capacity to adjust the perception of light. Simultaneous inactivation of SigB and SigD hampered growth also in high light. SigB is the most important group 2 sigma factor for salt acclimation, and elimination of all the other group 2 sigma factors slightly improved the salt tolerance of Synechocystis. Presence of only SigE allowed full salt acclimation including up-regulation of hspA and ggpS genes, but more slowly than SigB. Cells with only SigD acclimated to high salt but the acclimation processes differed from those of the control strain. Presence of only SigC prevented salt acclimation.