The innate immune system recognizes nucleic acids during infection or tissue damage; however, the mechanisms of intracellular recognition of DNA have not been fully elucidated. Here we show that intracellular administration of double-stranded B-form DNA (B-DNA) triggered antiviral responses including production of type I interferons and chemokines independently of Toll-like receptors or the helicase RIG-I. B-DNA activated transcription factor IRF3 and the promoter of the gene encoding interferon-beta through a signaling pathway that required the kinases TBK1 and IKKi, whereas there was substantial activation of transcription factor NF-kappaB independent of both TBK and IKKi. IPS-1, an adaptor molecule linking RIG-I and TBK1, was involved in B-DNA-induced activation of interferon-beta and NF-kappaB. B-DNA signaling by this pathway conferred resistance to viral infection in a way dependent on both TBK1 and IKKi. These results suggest that both TBK1 and IKKi are required for innate immune activation by B-DNA, which might be important in antiviral innate immunity and other DNA-associated immune disorders.

Glycolysis is one of the main pathways of carbon catabolism in Bacillus subtilis. Although the biochemical activity of glycolytic enzymes has been studied in detail, no information about the expression of glycolytic genes has so far been available in this organism. Therefore, transcriptional analysis of all glycolytic genes was performed. The genes cggR, gapA, pgk, tpi, pgm and eno, encoding the enzymes required for the interconversion of triose phosphates, are transcribed as a hexacistronic operon as demonstrated by Northern analysis. This gapA operon is repressed by the regulator CggR. The presence of sugars and amino acids synergistically results in the induction of the gapA operon. The transcriptional start site upstream of cggR was mapped by primer extension. Transcripts originating upstream of cggR are processed near the 3′ end of cggR. This endonucleolytic cleavage leads to differential stability of the resulting processing products: the monocistronic cggR message is very rapidly degraded, whereas the mRNA species encoding glycolytic enzymes exhibit much higher stability. An additional internal constitutive promoter was identified upstream of pgk. Thus, gapA is the most strongly regulated gene of this operon. The pfk pyk operon encoding phosphofructokinase and pyruvate kinase is weakly induced by glucose. In contrast, the genes pgi and fbaA, coding for phosphoglucoisomerase and fructose‐1,6‐bisphosphate aldolase, are constitutively expressed.

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Control of the glycolytic gapA operon by the catabolite control protein A in Bacillus subtilis: a novel mechanism of CcpA-mediated regulation hydrates as single sources of carbon and energy. Their catabolism involves three central pathways, i.e. glycolysis, the pentose phosphate shunt and the tricarboxylic acid (TCA) cycle (Sauer et al., 1996;Stülke and Hillen, 2000;Dauner et al., 2001;Sonenshein, 2002). In addition to the generation of reducing power and ATP by substratelevel phosphorylation, these pathways are also required for the generation of precursors for anabolic reactions. Thus, the activity of the central catabolic pathways has to be in balance with the anabolic capacity of the cells under any given condition. Genes encoding enzymes of glycolysis and the TCA cycle are tightly controlled by the presence of carbohydrates and amino acids. Although several enzymes of glycolysis are induced in the presence of glucose or other sugars, the TCA cycle is repressed under these conditions Tobisch et al., 1999;Fillinger et al., 2000;Jourlin-Castelli et al., 2000;.The mechanisms of regulation of carbon catabolism have been studied intensively in B. subtilis. The catabolite control protein A (CcpA) is central to carbon regulation. In the presence of glucose or other sugars, CcpA binds to target sites in front of catabolic operons, resulting in repression or activation of the target genes (Henkin, 1996;Stülke and Hillen, 2000). The DNA-binding activity of CcpA depends on the formation of cofactors. These are the HPr protein of the phosphotransferase system (PTS) and its regulatory paralogue, Crh. In the presence of glucose, HPr and Crh are phosphorylated on their regulatory phosphorylation site, Ser-46, by the metaboliteactivated HPr kinase/phosphatase (HPrK/P). Binding of HPr(Ser-P) or Crh(Ser-P) to CcpA triggers the DNAbinding activity Fujita et al., 1995;Galinier et al., 1997;Reizer et al., 1998).Bacillus subtilis genes controlled by CcpA have recently been identified using proteome and transcriptome analyses. Among the genes subject to CcpA-dependent repression are genes encoding enzymes of the TCA cycle, whereas glycolytic genes require a functional CcpA for induction Moreno et al., 2001;Yoshida et al., 2001). In addition, one of the major links between carbon and nitrogen metabolism in B. subtilis, the synthesis of glutamate, depends on CcpA (Faires et al., 1999). Although direct transcription repression or activation is the mechanism by which CcpA regulates many SummaryGlycolysis is one of the main pathways of carbon catabolism in Bacillus subtilis. Expression of the gapA gene encoding glyceraldehyde-3-phosphate dehydrogenase, the key enzyme of glycolysis from an energetic point of view, is induced by glucose and other sugars. Two regulators are involved in induction of the gapA operon, the product of the first gene of the operon, the CggR repressor, and catabolite control protein A (CcpA). CcpA is required for induction of the gapA operon by glucose. Genetic evidence has demonstrated that CcpA does not contr...

Modified vaccinia virus