Ribosomal dimerization factor YfiA is the major protein synthesized after abrupt glucose depletion in Lactococcus lactis
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We analyzed the response of the model bacterium <italic>Lactococcus lactis</i> to abrupt depletion of glucose after several generations of exponential growth. Glucose depletion resulted in a drastic drop in the energy charge accompanied by an extremely low GTP level and almost total arrest of protein synthesis. Strikingly the cell prioritized the continued synthesis of a few proteins, of which the ribosome dimerization factor YfiA was the most highly expressed. Transcriptome analysis showed no immediate decrease in total mRNA levels despite the lowered nucleotide pools, and only marginally increased levels of the <italic>yfiA</i> transcript. Severe up-regulation of genes in the FruR, CcpA, ArgR, and AhrC regulons were consistent with a downshift in carbon and energy source. Based upon the results we suggest that transcription proceeded long enough to record the transcriptome changes from activation of the FruR, CcpA, ArgR and AhrC regulons, while protein synthesis stopped due to an extremely low GTP concentration emerging few minutes after glucose depletion. The <italic>yfiA</i> deletion mutant exhibited a longer lag phase upon replenishment of glucose and a faster death rate after prolonged starvation supporting that YfiA mediated ribosome dimerization is important for keeping long-term starved cells viable and competent for growth-initiation.
Original language | English |
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Journal | Microbiology |
Volume | 162 |
Issue number | 10 |
Pages (from-to) | 1829-1839 |
Number of pages | 11 |
ISSN | 1350-0872 |
DOIs | |
Publication status | Published - Oct 2016 |
ID: 167217170