PBP2b plays a key role in both peripheral growth and septum positioning in Lactococcus lactis / Blandine David  

Public ISBD Faire une suggestion d'achat Titre : PBP2b plays a key role in both peripheral growth and septum positioning in Lactococcus lactis Type de document : document électronique Auteurs : Blandine David, Auteur ; Gabrielle Laurie Haustenne (Haustenne), Auteur ; Marie-Clémence Duchêne, Auteur ; Marie-Pierre Chapot-Chartier, Auteur ; Daniel Perez Nunez, Auteur Editeur : Centre National de la Recherche Scientifique Année de publication : 2018 Format : HTML Accompagnement : PDF Langues : Anglais (eng) Catégories : 579 Biologie des algues, champignons inférieurs, micro organismes (biologie descriptive et histoire naturelle des algues, champignons inférieurs, micro organismes ; microbiologie ; ouvrages généraux et interdisciplinaires sur les algues, les champignons inférieurs, les micro organismes ; protistes, protophytes, thallophytes) Tags : Lactococcus lactis  Pneumococcus  Phase contrast microscopy  Cell fusion  Transmission electron microscopy  Fluorescence imaging  Fluorescence microscopy  Fusion cellulaire  Imagerie par fluorescence  Microscopie à fluorescence  Microscopie électronique à transmission Index. décimale : 579 Résumé : Lactococcus lactis is an ovoid bacterium that forms filaments during planktonic and biofilm lifestyles by uncoupling cell division from cell elongation. In this work, we investigate the role of the leading peptidoglycan synthase PBP2b that is dedicated to cell elongation in ovo-cocci. We show that the localization of a fluorescent derivative of PBP2b remains associated to the septal region and superimposed with structural changes of FtsZ during both vegetative growth and filamentation indicating that PBP2b remains intimately associated to the division machinery during the whole cell cycle. In addition, we show that PBP2b-negative cells of L. lactis are not only defective in peripheral growth; they are also affected in septum positioning. This septation defect does not simply result from the absence of the protein in the cell growth machinery since it is also observed when PBP2b-deficient cells are complemented by a catalytically inactive variant of PBP2b. Finally, we show that round cells resulting from β-lactam treatment are not altered in septation, suggesting that shape elongation as such is not a major determinant for selection of the division site. Altogether, we propose that the specific PBP2b transpeptidase activity at the septum plays an important role for tag- ging future division sites during L. lactis cell cycle. En ligne : https://hal.science/hal-01806302 Format de la ressource électronique : HTML PBP2b plays a key role in both peripheral growth and septum positioning in Lactococcus lactis [document électronique] / Blandine David, Auteur ; Gabrielle Laurie Haustenne (Haustenne), Auteur ; Marie-Clémence Duchêne, Auteur ; Marie-Pierre Chapot-Chartier, Auteur ; Daniel Perez Nunez, Auteur . - Centre National de la Recherche Scientifique, 2018 . -  ; HTML + PDF. Langues : Anglais (eng) Catégories : 579 Biologie des algues, champignons inférieurs, micro organismes (biologie descriptive et histoire naturelle des algues, champignons inférieurs, micro organismes ; microbiologie ; ouvrages généraux et interdisciplinaires sur les algues, les champignons inférieurs, les micro organismes ; protistes, protophytes, thallophytes) Tags : Lactococcus lactis  Pneumococcus  Phase contrast microscopy  Cell fusion  Transmission electron microscopy  Fluorescence imaging  Fluorescence microscopy  Fusion cellulaire  Imagerie par fluorescence  Microscopie à fluorescence  Microscopie électronique à transmission Index. décimale : 579 Résumé : Lactococcus lactis is an ovoid bacterium that forms filaments during planktonic and biofilm lifestyles by uncoupling cell division from cell elongation. In this work, we investigate the role of the leading peptidoglycan synthase PBP2b that is dedicated to cell elongation in ovo-cocci. We show that the localization of a fluorescent derivative of PBP2b remains associated to the septal region and superimposed with structural changes of FtsZ during both vegetative growth and filamentation indicating that PBP2b remains intimately associated to the division machinery during the whole cell cycle. In addition, we show that PBP2b-negative cells of L. lactis are not only defective in peripheral growth; they are also affected in septum positioning. This septation defect does not simply result from the absence of the protein in the cell growth machinery since it is also observed when PBP2b-deficient cells are complemented by a catalytically inactive variant of PBP2b. Finally, we show that round cells resulting from β-lactam treatment are not altered in septation, suggesting that shape elongation as such is not a major determinant for selection of the division site. Altogether, we propose that the specific PBP2b transpeptidase activity at the septum plays an important role for tag- ging future division sites during L. lactis cell cycle. En ligne : https://hal.science/hal-01806302 Format de la ressource électronique : HTML

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