title: A putative sensor kinase, Hik31, is involved in the response of Synechocystis sp. strain PCC 6803 to the presence of glucose.
abstract: The reason(s) for glucose sensitivity in certain cyanobacterial strains is poorly understood. Inactivation of genes encoding the putative sensor kinase Hik31 in Synechocystis sp. strain PCC 6803 resulted in a mutant unable to grow in the presence of D-glucose. Sensitivities to D-glucose, its analogue 2-deoxy-D-glucose, and fructose, were alleviated in mutants in which glcP, encoding the glucose transporter, was inactivated. These data indicate that permeation of these substrates is required to inflict cell death. The mutant Deltahik31, and the glucose-sensitive strain of Synechocystis, do not possess glucokinase activity, although a transcript originating from glk, encoding glucokinase, is present. Inactivation of glk led to severe sensitivity to glucose, indicating that the presence of glucose itself, within the cells, inflicted this sensitivity. On the other hand, sensitivity to 2-deoxy-D-glucose was lower in Deltaglk, thus distinguishing between the effect of glucose itself and that of its analogue, which, in the absence of glucokinase activity, may not be phosphorylated. Addition of glucose led to a small rise in glucose-6-phosphate dehydrogenase activity in the wild type, but constitutive activity was observed in the Deltahik31 mutant regardless of the presence of glucose. Microarray analyses showed only small changes in the abundance of global transcripts in Synechocystis following glucose addition, but the transcription levels of several genes, including icfG, but not glk, were strongly affected by inactivation of hik31. The mechanism(s) whereby Hik31 is involved in glucose sensing and response is discussed.
authors.affiliation: Department of Plant and Environmental Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
authors.forename: Shira
authors.initials: S
authors.lastname: Kahlon
authors.affiliation: Department of Plant and Environmental Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
authors.forename: Karen
authors.initials: K
authors.lastname: Beeri
authors.affiliation: Bioscience Center, Nagoya University, Nagoya, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohkawa
authors.affiliation: Department of Biochemistry and Molecular Biology, Saitama University, Saitama, Japan.
authors.forename: Yukako
authors.initials: Y
authors.lastname: Hihara
authors.affiliation: Department of Plant and Environmental Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
authors.forename: Omer
authors.initials: O
authors.lastname: Murik
authors.affiliation: National Institute for Basic Biology, Okazaki, Japan.
authors.forename: Iwane
authors.initials: I
authors.lastname: Suzuki
authors.affiliation: Bioscience Center, Nagoya University, Nagoya, Japan.
authors.forename: Teruo
authors.initials: T
authors.lastname: Ogawa
authors.affiliation: Department of Plant and Environmental Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
authors.forename: Aaron
authors.initials: A
authors.lastname: Kaplan
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D020868:Gene Silencing; D005947:Glucose / Q000378:metabolism*; D000071677:Histidine Kinase; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D046939:Synechocystis / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D011494:Protein Kinases; D000071677:Histidine Kinase; D005947:Glucose