Premium
Proteome phenotyping of acid stress‐resistant mutants of Lactococcus lactis MG1363
Author(s) -
BudinVerneuil Aurélie,
Pichereau Vianney,
Auffray Yanick,
Ehrlich Dusko,
Maguin Emmanuelle
Publication year - 2007
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200600773
Subject(s) - lactococcus lactis , mutant , proteome , biology , mutagenesis , gene , strain (injury) , biochemistry , isobutyric acid , wild type , insertional mutagenesis , microbiology and biotechnology , bacteria , genetics , lactic acid , anatomy
To cope with medium acidity, Lactococcus lactis has evolved a number of inducible mechanisms commonly referred as acid stress response. To better understand the molecular basis of this response, several mutants constitutively tolerant to acidity were previously obtained by insertional random mutagenesis of L. lactis MG1363. Mutants in which the GMP synthase gene ( i.e. gua A), the (p)ppGpp synthase gene ( i.e. rel A*) or the high affinity phosphate transport system ( i.e. pst S) are inactivated are further characterized in this study. 2‐DE was performed and showed that 42, 26, and 35 protein spots are positively deregulated in the gua A, rel A*, and pst S mutants, respectively, as compared to the wild‐type strain. Most of these proteins were identified by MS. Proteomes comparison of the mutants gua A, rel A*, and pst S as well as the acid adaptation proteome of the wild‐type strain revealed (i) the presence of numerous overlaps and (ii) that only five proteins were overexpressed in the four conditions, suggesting that these proteins play a crucial role in the constitutive acid stress tolerance of the mutants and in the acid tolerance response of the wild‐type strain.