Translating Divergent Environmental Stresses into a Common Proteome Response through the Histidine Kinase 33 (Hik33) in a Model Cyanobacterium

Abstract

The histidine kinase Hik33 plays important roles in mediating cyanobacterial response to divergent types of abiotic stresses including cold, salt, high light (HL), and osmotic stresses. However, how these functions are regulated by Hik33 remains to be addressed. Using a hik33-deficient strain (Δhik33) of sp. PCC 6803 () and quantitative proteomics, we found that Hik33 depletion induces differential protein expression highly like that induced by divergent types of stresses. This typically includes downregulation of proteins in photosynthesis and carbon assimilation that are necessary for cell propagation, and upregulation of heat shock proteins, chaperons, and proteases that are important for cell survival. This observation indicates that depletion of Hik33 alone mimics divergent types of abiotic stresses, and that Hik33 could be important for preventing abnormal stress response in the normal condition. Moreover, we found most proteins of plasmid origin were significantly upregulated in Δhik33, though their biological significance remains to be addressed. Together, the systematically characterized Hik33-regulated cyanobacterial proteome, which is largely involved in stress responses, builds the molecular basis for Hik33 as a general regulator of stress responses.

cTAGE5/MEA6 plays a critical role in neuronal cellular components trafficking and brain development

“…Quantitative MS. The protein sample preparation of brain tissues for MS analysis and protocols of the MS analysis were performed as described previously with some modifications (53,54). Three WT and cKO mouse brains at P14 were dissected and lysed in the lysis buffer [0.4 M sucrose, 50 mM 3-(Nmorpholino) propanesulfonic acid (pH 7.0), 10 mM NaCl, 5 mM EDTA, and 0.5 mM PMSF].…”

Activation of the Oxidative Pentose Phosphate Pathway is Critical for Photomixotrophic Growth of a hik33‐Deletion Mutant of Synechocystis sp. PCC 6803

“…Bioinformatics and statistical analyses were performed using the software Perseus (version 1.5.4.1) . Student's t ‐test with a p ‐value < 0.05 was used to filter for proteins that are quantitated with high confidence, which were further filtered with a fold change of 1.4 for proteins with significant difference in expression as previously described . Fisher's‐exact text with a p ‐value < 0.01 and an enrichment factor > 1.5 was used to identify enriched functions.…”

“…The histidine kinase 33 (Hik33, sll0698 ) is a general regulator for stress responses in cyanobacteria. Deletion of hik33 induces a strong stress‐like response in Synechocystis , including severely repressed photosynthetic machineries and photoautotrophic growth, differential expression of stress‐responsive proteins, and high sensitivity to abiotic stresses such as high light, high salts, and low temperature . Glucose can effectively rescue the growth of the hik33 ‐deletion mutant (Δhik33), and the photomixotrophic growth of the mutant is only slightly repressed compared with that of the wild type (WT).…”

Nitrogen chlorosis in unicellular cyanobacteria – a developmental program for surviving nitrogen deprivation

“…Of the 47 histidine kinases in Synechocystis, Hik 11 is one of three essential ones (Kotajima et al, 2014). Hik33, the Synechocystis homologue of NblS, mediates responses to diverse abiotic stresses, among them cold, salt and high light stress (Ge et al, 2017). The induction of Hik33 could be related to the repression of the nblA1-nblA2 operon to prevent the degradation of the newly arising phycobilisomes.…”