title: Acclimation to High CO2Requires theωSubunit of the RNA Polymerase inSynechocystis.
abstract: Inactivation of the nonessential ω-subunit of the RNA polymerase core in the ΔrpoZ strain of the model cyanobacteriumSynechocystissp. PCC 6803 leads to a unique high-CO2-sensitive phenotype. Supplementing air in the growth chamber with 30 mL L-1(3%) CO2accelerated the growth rate of the control strain (CS) 4-fold, whereas ΔrpoZ did not grow faster than under ambient air. The slow growth of ΔrpoZ during the first days in high CO2was due to the inability of the mutant cells to adjust photosynthesis to high CO2The light-saturated photosynthetic activity of ΔrpoZ in high CO2was only half of that measured in CS, Rubisco content was one-third lower, and cells of ΔrpoZ were not able to increase light-harvesting phycobilisome antenna like CS upon high-CO2treatment. In addition, altered structural and functional organization of photosystem I and photosystem II were detected in the ΔrpoZ strain compared with CS when cells were grown in high CO2but not in ambient air. Moreover, respiration of ΔrpoZ did not acclimate to high CO2Unlike the photosynthetic complexes, the RNA polymerase complex and ribosomes were produced in high CO2similarly as in CS Our results indicate that the deletion of the ω-subunit specifically affects photosynthesis and respiration, but transcription and translation remain active. Thus, the specific effect of the ω-subunit on photosynthesis but not on all household processes suggests that the ω-subunit might have a regulatory function in cyanobacteria.
authors.affiliation: Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and.|Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.).
authors.forename: Juha
authors.identifier: http://orcid.org/0000-0003-3750-7318
authors.initials: J
authors.lastname: Kurkela
authors.affiliation: Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and.|Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.).
authors.forename: Kaisa
authors.initials: K
authors.lastname: Hakkila
authors.affiliation: Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and.|Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.).
authors.forename: Taras
authors.initials: T
authors.lastname: Antal
authors.affiliation: Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and taityy@utu.fi.|Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.) taityy@utu.fi.
authors.forename: Taina
authors.identifier: http://orcid.org/0000-0003-0591-8630
authors.initials: T
authors.lastname: Tyystjärvi
mesh_terms: D000064:Acclimatization; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018507:Gene Expression Regulation, Developmental; D008027:Light; D009154:Mutation; D010788:Photosynthesis / Q000235:genetics / Q000528:radiation effects; D045331:Photosystem I Protein Complex / Q000235:genetics / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000378:metabolism; D045524:Phycobilisomes / Q000378:metabolism / Q000528:radiation effects; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D046939:Synechocystis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D045524:Phycobilisomes; D021122:Protein Subunits; D002245:Carbon Dioxide; D012321:DNA-Directed RNA Polymerases