Dynamics and Cell-Type Specificity of the DNA Double-Strand Break Repair Protein RecN in the Developmental Cyanobacterium Anabaena sp. Strain PCC 7120

Sheng Hu (1) , Jinglan Wang (1) , Li Wang (2) , Cheng-Cai Zhang (2) , Wen-Li Chen (1)

1 State Key Laboratory of Agricultural Microbiology
2 LCB - Laboratoire de chimie bactérienne

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 filamen-tous cyanobacterium Anabaena sp. strain PCC 7120 is capable of forming heterocysts for N 2 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.

Mots clés: BACILLUS-SUBTILIS RECN; HETEROCYST DIFFERENTIATION; ESCHERICHIA-COLI; FILAMENTOUS CYANOBACTERIUM; PATTERN-FORMATION; SP PCC-7120; GENES; DIVISION; REPLICATION; RECRUITMENT

Domaines: Biodiversité

Sheng Hu, Jinglan Wang, Li Wang, Cheng-Cai Zhang, Wen-Li Chen. Dynamics and Cell-Type Specificity of the DNA Double-Strand Break Repair Protein RecN in the Developmental Cyanobacterium Anabaena sp. Strain PCC 7120. PLoS ONE, 2015, 10 (e0139362), ⟨10.1371/journal.pone.0139362⟩. ⟨hal-01235678⟩