Identification of a stress-induced factor of Corynebacterineae that is involved in the regulation of the outer membrane lipid composition. - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Journal of Bacteriology Année : 2009

Identification of a stress-induced factor of Corynebacterineae that is involved in the regulation of the outer membrane lipid composition.

Xavier Meniche
  • Fonction : Auteur
Emilie Huc
  • Fonction : Auteur
Françoise Laval
  • Fonction : Auteur
Marielle Tropis
  • Fonction : Auteur
Nicolas Bayan
Damien Portevin
  • Fonction : Auteur
Christophe Guilhot
Mamadou Daffé
  • Fonction : Auteur

Résumé

Corynebacterineae are gram-positive bacteria that possess a true outer membrane composed of mycolic acids and other lipids. Little is known concerning the modulation of mycolic acid composition and content in response to changes in the bacterial environment, especially temperature variations. To address this question, we investigated the function of the Rv3802c gene, a gene conserved in Corynebacterineae and located within a gene cluster involved in mycolic acid biosynthesis. We showed that the Rv3802 ortholog is essential in Mycobacterium smegmatis, while its Corynebacterium glutamicum ortholog, NCgl2775, is not. We provided evidence that the NCgl2775 gene is transcriptionally induced under heat stress conditions, and while the corresponding protein has no detectable activity under normal growth conditions, the increase in its expression triggers an increase in mycolic acid biosynthesis concomitant with a decrease in phospholipid content. We demonstrated that these lipid modifications are part of a larger outer membrane remodeling that occurs in response to exposure to a moderately elevated temperature (42 degrees C). In addition to showing an increase in the ratio of saturated corynomycolates to unsaturated corynomycolates, our results strongly suggested that the balance between mycolic acids and phospholipids is modified inside the outer membrane following a heat challenge. Furthermore, we showed that these lipid modifications help the bacteria to protect against heat damage. The NCgl2775 protein and its orthologs thus appear to be a protein family that plays a role in the regulation of the outer membrane lipid composition of Corynebacterineae under stress conditions. We therefore propose to name this protein family the envelope lipids regulation factor (ElrF) family.

Dates et versions

hal-00529742 , version 1 (26-10-2010)

Identifiants

Citer

Xavier Meniche, Cécile Labarre, Célia de Sousa-d'Auria, Emilie Huc, Françoise Laval, et al.. Identification of a stress-induced factor of Corynebacterineae that is involved in the regulation of the outer membrane lipid composition.. Journal of Bacteriology, 2009, 191 (23), pp.7323-32. ⟨10.1128/JB.01042-09⟩. ⟨hal-00529742⟩
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