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Growth phase dependent regulation of protein composition in Rhodopirellula baltica
Author(s) -
Gade Dörte,
Stührmann Torben,
Reinhardt Richard,
Rabus Ralf
Publication year - 2005
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2005.00784.x
Subject(s) - biology , pentose phosphate pathway , biochemistry , downregulation and upregulation , baltica , citric acid cycle , enzyme , amino acid , protein biosynthesis , microbiology and biotechnology , gene , glycolysis , paleontology , ordovician
Summary Growth phase dependent changes of protein composition in the marine bacterium Rhodopirellula baltica were quantitatively monitored by applying the two‐dimensional difference gel electrophoresis (2D DIGE) technology. The number of regulated proteins (fold changes in protein abundance > |2|) increased from early (10) to late stationary growth phase (179), with fold changes reaching maximal values of 40. About 110 of these regulated protein spots were analysed by MALDI‐TOF‐MS and identified by mapping of peptide masses. Results indicate an opposing regulation of tricarboxylic acid cycle and oxidative pentose phosphate cycle, a downregulation of several enzymes involved in amino acid biosynthesis and an upregulation of the alternative sigma factor σ H in stationary phase. Interestingly, 26 proteins of unknown function were up‐ or downregulated in the stationary phase. Several proteins were specifically regulated during growth on solid surface (agar plates). These proteins could possibly be involved in the development of the different R. baltica morphotypes, i.e. motile swarmer cells and sessile cell aggregates (so‐called rosettes).