Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.13.3 (histidine kinase)
2,405 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adenylate cyclase genes, designated cyaA, cyaB1, cyaB2, cyaC, and cyaD, were isolated from the filamentous cyanobacterium Anabaena sp. strain PCC 7120 by complementation of a strain of Escherichia coli defective for the presence of cya. These genes encoded polypeptides consisting of 735, 859, 860, 1,155, and 546 amino acid residues, respectively. Deduced amino acid sequences of the regions near the C-terminal ends of these cya genes were similar to those of catalytic domains of eukaryotic adenylate cyclases. The remaining part of each cya gene towards its N-terminal end showed a characteristic structure. CyaA had two putative membrane-spanning regions. Both CyaB1 and CyaB2 had regions that were very similar to the cyclic GMP (cGMP)-binding domain of cGMP-stimulated cGMP phosphodiesterase. CyaC consisted of four distinct domains forming sequentially from the N terminus: a response regulator-like domain, a histidine kinase-like domain, a response regulator-like domain, and the catalytic domain of adenylate cyclase. CyaD contained the forkhead-associated domain in its N-terminal region. Expression of these genes was examined by reverse transcription-PCR. The transcript of cyaC was shown to be predominant in this cyanobacterium. The cellular cyclic AMP level in the disruptant of the cyaC mutant was much lower than that in the wild type.
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PMID:Isolation and characterization of multiple adenylate cyclase genes from the cyanobacterium Anabaena sp. strain PCC 7120. 917 4

A histidine kinase protein (Cph1) with sequence homology and spectral characteristics very similar to those of the plant phytochrome has been recently identified in the cyanobacterium Synechocystis sp. strain PCC 6803. Cph1 together with Rcp1 (a protein homologue to the response regulator CheY) forms a light-regulated two-component system whose function is presently unknown. Levels of cph1 rcp1 mRNA increase in the dark and decrease upon reillumination. A dark-mediated increase in cph1 rcp1 mRNA levels was inhibited by the presence of glucose, but not by inhibition of the photosynthetic electron flow. The half-life of cph1 rcp1 transcript in the light was about fourfold shorter than in the dark, indicating that control of cph1 rcp1 transcript stability is one of the mechanisms by which light regulates expression of the cyanobacterial phytochrome. After 15 min of darkness, 3-min pulses of red, blue, green, and far-red light were equally efficient in decreasing the cph1 rcp1 mRNA levels. Red light downregulation was not reversed by far-red light, suggesting that cph1 rcp1 mRNA levels are not controlled by a phytochrome-like photoreceptor. Furthermore, a Synechocystis strain containing an H538R Cph1 point mutation, unable to phosphorylate Rcp1, shows normal light-dark regulation of the cph1 rcp1 transcript levels. Our data suggest a role of cyanobacterial phytochrome in the control of processes required for adaptation in light-dark and dark-light transitions.
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PMID:Light-dependent regulation of cyanobacterial phytochrome expression. 1061 60

Both regulated expression of the clock genes kaiA, kaiB, and kaiC and interactions among the Kai proteins are proposed to be important for circadian function in the cyanobacterium Synechococcus sp. strain PCC 7942. We have identified the histidine kinase SasA as a KaiC-interacting protein. SasA contains a KaiB-like sensory domain, which appears sufficient for interaction with KaiC. Disruption of the sasA gene lowered kaiBC expression and dramatically reduced amplitude of the kai expression rhythms while shortening the period. Accordingly, sasA disruption attenuated circadian expression patterns of all tested genes, some of which became arrhythmic. Continuous sasA overexpression eliminated circadian rhythms, whereas temporal overexpression changed the phase of kaiBC expression rhythm. Thus, SasA is a close associate of the cyanobacterial clock that is necessary to sustain robust circadian rhythms.
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PMID:A kaiC-interacting sensory histidine kinase, SasA, necessary to sustain robust circadian oscillation in cyanobacteria. 1078 37

The gene products of sll0337 and slr0081 in Synechocystis sp. PCC 6803 have been identified as the homologues of the Escherichia coli phosphate-sensing histidine kinase PhoR and response regulator PhoB, respectively. Interruption of sll0337, the gene encoding the histidine protein kinase, by a spectinomycin-resistance cassette blocked the induction of alkaline phosphatase activity under phosphate-limiting conditions. A similar result was obtained when slr0081, the gene encoding the response regulator, was interrupted with a cassette conferring resistance to kanamycin. In addition, the phosphate-specific transport system was not up-regulated in our mutants when phosphate was limiting. Unlike other genes for bacterial phosphate-sensing two-component systems, sll0337 and slr0081 are not present in the same operon. Although there are three assignments for putative alkaline phosphatase genes in the Synechocystis sp. PCC 6803 genome, only sll0654 expression was detected by northern analysis under phosphate limitation. This gene codes for a 149 kDa protein that is homologous to the cyanobacterial alkaline phosphatase reported in Synechococcus sp. PCC 7942 [Ray, J.M., Bhaya, D., Block, M.A. and Grossman, A.R. (1991) J. Bact. 173: 4297-4309]. An alignment identified a conserved 177 amino acid domain that was found at the N-terminus of the protein encoded by sll0654 but at the C-terminus of the protein in Synechococcus sp. PCC 7942.
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PMID:Characterization of a two-component signal transduction system involved in the induction of alkaline phosphatase under phosphate-limiting conditions in Synechocystis sp. PCC 6803. 1128 5

The HliA protein of the cyanobacterium Synechococcus elongatus PCC 7942 is a small, thylakoid-associated protein that appears to play a role in photoprotection; its transcript rapidly accumulates in response to high-intensity light (HL) and the hli gene family is required for survival of cells in high light. In order to discover regulatory factors involved in HL acclimation in cyanobacteria, a screen was performed for chemically generated mutants unable to properly control expression of the hliA gene in response to HL. One such mutant was identified, and complementation analysis led to the identification of the affected gene, designated nblS. Based on its deduced protein sequence, NblS appears to be a membrane-bound, PAS-domain-bearing, sensor histidine kinase of two-component regulatory systems in bacteria. The nblS mutant was unable to properly control light intensity-mediated expression of several other photosynthesis-related genes, including all three psbA genes and the cpcBA genes. The mutant was also unable to control expression of the hliA and psbA genes in response to low-intensity blue/UV-A light, a response that may be related to the HL-mediated regulation of the genes. Additionally, in response to nutrient deprivation, the nblS mutant was unable to properly control accumulation of the nblA transcript and associated degradation of the light-harvesting phycobilisomes. The nblS mutant dies more rapidly than wild-type cells following exposure to HL or nutrient deprivation, likely due to its inability to properly acclimate to these stress conditions. Thus, the NblS protein is involved in the control of a number of processes critical for altering the photosynthetic apparatus in response to both HL and nutrient stress conditions.
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PMID:nblS, a gene involved in controlling photosynthesis-related gene expression during high light and nutrient stress in Synechococcus elongatus PCC 7942. 1194 63

Elemental manganese is essential for the production of molecular oxygen by cyanobacteria, plants, and algae. In the cyanobacterium Synechocystis sp. PCC 6803, transcription of the mntCAB operon, encoding a high affinity Mn transporter, occurs under Mn starvation (nm Mn) conditions but not in Mn-sufficient (microm Mn) growth medium. Using a strain in which the promoter of this operon directs the transcription of the luxAB reporter genes, we determined that inactivation of the slr0640 gene, which encodes a histidine kinase sensor protein component of a two-component signal transduction system, resulted in constitutive high levels of lux luminescence. Systematic targeted inactivation mutagenesis also identified slr1837 as the gene encoding the corresponding response regulator protein. We have named these two genes manS (manganese-sensor) and manR (manganese-regulator), respectively. A polyhistidine-tagged form of the ManS protein was localized in the Synechocystis 6803 cell membrane. Directed replacement of the conserved catalytic His-205 residue of this protein by Leu abolished its activity, although the mutated protein was present in cyanobacterial membrane. This mutant also showed suboptimal rates of Mn uptake under either Mn-starved or Mn-sufficient growth condition. These data suggest that the ManS/ManR two-component system plays a central role in the homeostasis of manganese in Synechocystis 6803 cells.
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PMID:A two-component signal transduction pathway regulates manganese homeostasis in Synechocystis 6803, a photosynthetic organism. 1203 66

The two ycf27 genes from the filamentous cyanobacterium Tolypothrix PCC 7601 have been cloned and sequenced. These two genes, previously designated rpaA and rpaB, encode putative transcriptional regulators of the 'OmpR' family. In Synechocystis PCC 6803, homologous genes have been linked to the regulation of transfer of excitation energy from the phycobilisome to photosystem (PS) I and PSII respectively. Partial clones from Spirulina platensis, Dactylococcopsis salina and Synechococcus PCC 7002 have also been sequenced. A table of identity between the proteins confirms that RpaB belongs in the same family as the algal ycf27 proteins. However, RpaA is a rather different protein and should lose the designation ycf27. The loss of rpaB from the plastid genomes of eukaryotic algae is associated with the loss of phycobiliproteins, so it is likely that this gene performs a similar role in algae to that in cyanobacteria. The implications for chloroplast evolution are discussed along with the possible identity of the cognate histidine kinase gene in the plastid genomes.
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PMID:The ycf27 genes from cyanobacteria and eukaryotic algae: distribution and implications for chloroplast evolution. 1220 68

The stress imposed on living organisms by hyperosmotic conditions and low temperature appears to be perceived via changes in the physical state of membrane lipids. We compared genome-wide patterns of transcription between wild-type Synechocystis sp. PCC 6803 and cells with a mutation in the histidine kinase Hik33 using a DNA microarray. Our results indicated that Hik33 regulated the expression of both osmostress-inducible and cold-inducible genes. The respective genes that were regulated by Hik33 under hyperosmotic and low-temperature conditions were, for the most part, different from one another. However, Hik33 also regulated the expression of a set of genes whose expression was induced both by osmotic stress and by cold stress. These results indicate that Hik33 is involved in responses to osmotic stress and low-temperature stress but that the mechanisms of the responses differ.
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PMID:The histidine kinase Hik33 perceives osmotic stress and cold stress in Synechocystis sp PCC 6803. 1242 Dec 99

A sudden decrease in ambient temperature induces the expression of a number of genes in poikilothermic organisms. We report here that the cold inducibility of gene expression in Synechocystis sp. PCC 6803 was enhanced by the rigidification of membrane lipids that was engineered by disruption of genes for fatty acid desaturases. DNA microarray analysis revealed that cold-inducible genes could be divided into three groups according to the effects of the rigidification of membrane lipids. The first group included genes whose expression was not induced by cold in wild-type cells but became strongly cold-inducible upon rigidification of membrane lipids. This group included certain heat-shock genes, genes for subunits of the sulfate transport system, and the hik34 gene for a histidine kinase. The second group consisted of genes whose cold inducibility was moderately enhanced by the rigidification of membrane lipids. Most genes in this group encoded proteins of as yet unknown function. The third group consisted of genes whose cold inducibility was unaffected by the rigidification of membrane lipids. This group included genes for an RNA helicase and an RNA-binding protein. DNA microarray analysis also indicated that the rigidification of membrane lipids had no effect on the heat inducibility of gene expression. Hik33, a cold-sensing histidine kinase, regulated the expression of most genes in the second and third groups but of only a small number of genes in the first group, an observation that suggests that the cold-inducible expression of genes in the first group might be regulated by a cold sensor that remains to be identified.
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PMID:Gene-engineered rigidification of membrane lipids enhances the cold inducibility of gene expression in synechocystis. 1250 18

Living organisms respond to phosphate limitation by expressing various genes whose products maintain an appropriate range of phosphate concentrations within each cell. We identified previously a two component system, which consists of histidine kinase SphS and its cognate response regulator SphR, which regulates the expression of the phoA gene for alkaline phosphatase under phosphate-limiting conditions in the cyanobacterium Synechocystis sp. PCC 6803. In the present study, we used DNA microarrays to investigate the role of SphS and SphR in the regulation of the genome-wide expression of genes in response to phosphate limitation. In wild-type cells, phosphate limitation strongly induced the expression of 12 genes with induction factors greater than 7. These genes were included in three clusters of genes, namely, the pst1 and pst2 clusters that encode phosphate transporters; the phoA gene and the nucH gene for the extracellular nuclease. Phosphate limitation strongly repressed the expression of only the urtA gene with induction factors below 0.2. Inactivation of either of SphS or SphR completely eliminated the phosphate limitation-inducible expression of the 12 genes and the phosphate limitation-repressible expression of the urtA gene. These results suggest that the SphS-SphR two component system in Synechocystis sp. PCC 6803 is the dominant sensory system that controls gene expression in response to phosphate limitation.
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PMID:The SphS-SphR two component system is the exclusive sensor for the induction of gene expression in response to phosphate limitation in synechocystis. 1470 28


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