Annick Janicki

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The cyanobacterial phylum includes oxygenic photosynthetic prokaryotes of a wide variety of morphologies, metabolisms and ecologies. Their adaptation to their various ecological niches is mainly achieved by sophisticated regulatory mechanisms and depends on a fine cross-talk between them. We assessed the global transcriptomic response of the filamentous(More)
The inactivation of sll0776 (spkD), a gene encoding a protein Ser/Thr kinase in Synechocystis PCC 6803, led to a pleiotropic phenotype of the SpkD null mutant. This mutant is impaired in its growth ability under low concentration of inorganic carbon (C(i)), though its C(i)-uptake system is not affected. Addition of glucose, phosphoglyceraldehyde or pyruvate(More)
Non-ribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) are necessary for the production of a variety of secondary metabolites, such as siderophores involved in iron acquisition. In response to iron limitation, the cyanobacterium Anabaena sp. strain PCC 7120 synthesizes several siderophores. The chromosome of this organism contains a large(More)
NifS-like cysteine desulfurases are widespread enzymes involved in the mobilization of sulfur from cysteine. The genome of the filamentous diazotrophic cyanobacterium Anabaena PCC 7120 contains four open reading frames potentially encoding NifS-like proteins. One of them, alr2505, belongs to the pkn22 operon, which enables Anabaena to cope with oxidative(More)
The overoxidation of 2-Cys peroxiredoxins (Prxs) into a sulfinic form was thought to be an irreversible protein inactivation process until sulfiredoxins (Srxs) were discovered. These are enzymes occurring among eukaryotes, which are able to reduce sulfinylated Prxs. Although Prxs are present in the three domains of life, their reduction by Srxs has been(More)
The filamentous cyanobacterium Anabaena sp. strain PCC 7120 can form heterocysts for N(2) fixation. Initiation of heterocyst differentiation depends on mutual regulation of ntcA and hetR. Control of hetR expression by NtcA is partially mediated by nrrA, but other factors must be involved in this regulation. Anabaena has two closely related PP2C-type protein(More)
patA expression is induced 3 to 6 h after nitrogen step-down. We establish that the transcription of patA is under the positive control of NtcA. The patA promoter region shows two conserved NtcA-binding boxes. These NtcA-binding sites and their interaction with NtcA are key elements for patA expression in heterocysts.