title: Dynamics and Cell-Type Specificity of the DNA Double-Strand Break Repair Protein RecN in the Developmental Cyanobacterium Anabaena sp. Strain PCC 7120.
abstract: DNA replication and repair are two fundamental processes required in life proliferation and cellular defense and some common proteins are involved in both processes. The filamentous cyanobacterium Anabaena sp. strain PCC 7120 is capable of forming heterocysts for N2 fixation in the absence of a combined-nitrogen source. This developmental process is intimately linked to cell cycle control. In this study, we investigated the localization of the DNA double-strand break repair protein RecN during key cellular events, such as chromosome damaging, cell division, and heterocyst differentiation. Treatment by a drug causing DNA double-strand breaks (DSBs) induced reorganization of the RecN focus preferentially towards the mid-cell position. RecN-GFP was absent in most mature heterocysts. Furthermore, our results showed that HetR, a central player in heterocyst development, was involved in the proper positioning and distribution of RecN-GFP. These results showed the dynamics of RecN in DSB repair and suggested a differential regulation of DNA DSB repair in vegetative cell and heterocysts. The absence of RecN in mature heterocysts is compatible with the terminal nature of these cells.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, China.
authors.forename: Jinglan
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Aix-Marseille Université and Laboratoire de Chimie Bactérienne (UMR7283), 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors.forename: Cheng-Cai
authors.initials: CC
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, 430070 Wuhan, China.
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Chen
mesh_terms: D017033:Anabaena / Q000201:enzymology* / Q000254:growth & development / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000032:analysis / Q000502:physiology*; D002455:Cell Division; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D004262:DNA Restriction Enzymes / Q000032:analysis / Q000502:physiology*; D004269:DNA, Bacterial / Q000187:drug effects / Q000378:metabolism; D005557:Formaldehyde / Q000494:pharmacology; D017930:Genes, Reporter; D016685:Mitomycin / Q000494:pharmacology; D009153:Mutagens / Q000494:pharmacology; D009268:Nalidixic Acid / Q000494:pharmacology; D009586:Nitrogen Fixation; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000378:metabolism; D013347:Subcellular Fractions / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D009153:Mutagens; D011993:Recombinant Fusion Proteins; C067403:HetR protein, Bacteria; D005557:Formaldehyde; D009268:Nalidixic Acid; D016685:Mitomycin; D004262:DNA Restriction Enzymes; C047879:RecN protein, Bacteria