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Mechanisms of High Temperature Resistance of Synechocystis sp. PCC 6803: An Impact of Histidine Kinase 34.

Červený J, Sinetova MA, Zavřel T, Los DA - Life (Basel) (2015)

Bottom Line: PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses.We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C.In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

View Article: PubMed Central - PubMed

Affiliation: Department of Adaptation Biotechnologies, Global Change Research Centre, Academy of Sciences of the Czech Republic, Drásov 470, CZ-66424 Drásov, Czech Republic. cerveny.j@czechglobe.cz.

ABSTRACT
Synechocystis sp. PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses. Changes in transcriptome, proteome, lipidome, and photosynthesis in response to short term heat stress are well studied in this organism, and histidine kinase 34 (Hik34) is shown to play an important role in mediating such response. Corresponding data on long term responses, however, are fragmentary and vary depending on parameters of experiments and methods of data collection, and thus are hard to compare. In order to elucidate how the early stress responses help cells to sustain long-term heat stress, as well as the role of Hik34 in prolonged acclimation, we examined the resistance to long-term heat stress of wild-type and ΔHik34 mutant of Synechocystis. In this work, we were able to precisely control the long term experimental conditions by cultivating Synechocystis in automated photobioreactors, measuring selected physiological parameters within a time range of minutes. In addition, morphological and ultrastructural changes in cells were analyzed and western blotting of individual proteins was used to study the heat stress-affected protein expression. We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C. In contrast, while ΔHik34 mutant cells were resistant to heat stress within its first hours, they could not recover after 24 h long high temperature treatment. We demonstrated that the early induction of HspA expression and maintenance of high amount of other HSPs throughout the heat incubation is critical for successful adaptation to long-term stress. In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

No MeSH data available.


Related in: MedlinePlus

Western-blot analysis of heat-stress inducible proteins ClpB1, DnaK2, GroEL Hsp 16.6 and “constitutive” proteins ClpB2, RbcL, D1, KatG in wild-type and ΔHik34 mutant cells during 24 h of heat stress at 44 °C followed by recovery at 32°C. Last row shows parts of Coomassie R-250-stained gels. Cells were analyzed in 2 independent experiments. Typical blots are shown.
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life-05-00676-f007: Western-blot analysis of heat-stress inducible proteins ClpB1, DnaK2, GroEL Hsp 16.6 and “constitutive” proteins ClpB2, RbcL, D1, KatG in wild-type and ΔHik34 mutant cells during 24 h of heat stress at 44 °C followed by recovery at 32°C. Last row shows parts of Coomassie R-250-stained gels. Cells were analyzed in 2 independent experiments. Typical blots are shown.

Mentions: Changes in the protein levels of four heat-shock proteins, ClpB1, DnaK, GroEL, and HspA, were analyzed by western blot technique during 24 h of heat stress at 44 °C followed by 12 h of recovery at 32 °C in wild-type and 39 h of recovery in ΔHik34 mutant cells (Figure 7). Equivalent analysis has been also performed for constitutive, non-heat-inducible proteins, such as core PSII protein D1, large subunit (LS) of CO2 fixating Rubisco, catalase KatG, and protease ClpB2.


Mechanisms of High Temperature Resistance of Synechocystis sp. PCC 6803: An Impact of Histidine Kinase 34.

Červený J, Sinetova MA, Zavřel T, Los DA - Life (Basel) (2015)

Western-blot analysis of heat-stress inducible proteins ClpB1, DnaK2, GroEL Hsp 16.6 and “constitutive” proteins ClpB2, RbcL, D1, KatG in wild-type and ΔHik34 mutant cells during 24 h of heat stress at 44 °C followed by recovery at 32°C. Last row shows parts of Coomassie R-250-stained gels. Cells were analyzed in 2 independent experiments. Typical blots are shown.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390874&req=5

life-05-00676-f007: Western-blot analysis of heat-stress inducible proteins ClpB1, DnaK2, GroEL Hsp 16.6 and “constitutive” proteins ClpB2, RbcL, D1, KatG in wild-type and ΔHik34 mutant cells during 24 h of heat stress at 44 °C followed by recovery at 32°C. Last row shows parts of Coomassie R-250-stained gels. Cells were analyzed in 2 independent experiments. Typical blots are shown.
Mentions: Changes in the protein levels of four heat-shock proteins, ClpB1, DnaK, GroEL, and HspA, were analyzed by western blot technique during 24 h of heat stress at 44 °C followed by 12 h of recovery at 32 °C in wild-type and 39 h of recovery in ΔHik34 mutant cells (Figure 7). Equivalent analysis has been also performed for constitutive, non-heat-inducible proteins, such as core PSII protein D1, large subunit (LS) of CO2 fixating Rubisco, catalase KatG, and protease ClpB2.

Bottom Line: PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses.We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C.In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

View Article: PubMed Central - PubMed

Affiliation: Department of Adaptation Biotechnologies, Global Change Research Centre, Academy of Sciences of the Czech Republic, Drásov 470, CZ-66424 Drásov, Czech Republic. cerveny.j@czechglobe.cz.

ABSTRACT
Synechocystis sp. PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses. Changes in transcriptome, proteome, lipidome, and photosynthesis in response to short term heat stress are well studied in this organism, and histidine kinase 34 (Hik34) is shown to play an important role in mediating such response. Corresponding data on long term responses, however, are fragmentary and vary depending on parameters of experiments and methods of data collection, and thus are hard to compare. In order to elucidate how the early stress responses help cells to sustain long-term heat stress, as well as the role of Hik34 in prolonged acclimation, we examined the resistance to long-term heat stress of wild-type and ΔHik34 mutant of Synechocystis. In this work, we were able to precisely control the long term experimental conditions by cultivating Synechocystis in automated photobioreactors, measuring selected physiological parameters within a time range of minutes. In addition, morphological and ultrastructural changes in cells were analyzed and western blotting of individual proteins was used to study the heat stress-affected protein expression. We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C. In contrast, while ΔHik34 mutant cells were resistant to heat stress within its first hours, they could not recover after 24 h long high temperature treatment. We demonstrated that the early induction of HspA expression and maintenance of high amount of other HSPs throughout the heat incubation is critical for successful adaptation to long-term stress. In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

No MeSH data available.


Related in: MedlinePlus