Proteomic Analysis of Stationary Phase in the Marine Bacterium 'Candidatus Pelagibacter ubique'
Candidatus Pelagibacter ubique, an abundant marine alphaproteobacterium, subsists in nature at low ambient nutrient concentrations and may often be exposed to nutrient limitation, but its genome revealed no evidence of global regulatory adaptations to stationary phase. We used high-resolution capillary liquid chromatography (LC) coupled online to an LTQ mass spectrometer to build an Accurate Mass and Time (AMT) tag library, and employed the AMT tag approach to quantitatively examine proteome differences between exponentially growing and stationary phase Cand. P. ubique cells cultivated in a seawater medium. The AMT tag library represented 72% of the predicted protein coding genes. Stationary phase protein abundance increased for OsmC, which mitigates oxidative damage, and for molecular chaperones, enzymes involved in methionine and cysteine biosynthesis, proteins involved in rho-dependent transcription termination, and the signal transduction enzymes CheY-FisH and ChvG. Our findings indicate that Cand. P. ubique responds adaptively to stationary phase by increasing the abundance of a suite of proteins that contribute to homeostasis, but does not undergo major proteome remodeling. We speculate that this limited response may enable Cand. P. ubique to cope with ambient conditions in which nutrients are often insufficient for short periods, and the ability to resume growth overrides the capacity for long term survival afforded by more comprehensive global stationary phase responses.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 937380
- Report Number(s):
- PNNL-SA-59403; AEMIDF; KP1501021; TRN: US200819%%103
- Journal Information:
- Applied and Environmental Microbiology, 74(13):4091-4100, Vol. 74, Issue 13; ISSN 0099-2240
- Country of Publication:
- United States
- Language:
- English
Similar Records
Proteome Remodeling in Response to Sulfur Limitation in “ Candidatus Pelagibacter ubique”
Proteomic Analysis of Stationary Phase in the Marine Bacterium "Candidatus Pelagibacter ubique"