| Full text | |
| Author(s): |
da Silva, Carolina A. P. T.
[1]
;
Lourenco, Rogerio F.
[2]
;
Mazzon, Ricardo R.
[1, 3]
;
Ribeiro, Rodolfo A.
[1]
;
Marques, Marilis V.
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Sao Paulo, Inst Ciencias Biomed, Dept Microbiol, Ave Prof Lineu Prestes 1374, BR-05508000 Sao Paulo, SP - Brazil
[2] Univ Sao Paulo, Inst Quim, Dept Bioquim, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil
[3] Univ Fed Santa Catarina, Ctr Ciencias Biol, Dept Microbiol Imunol & Parasitol, Campus Univ Trindade, Caixa Postal 476, BR-88040900 Florianopolis, SC - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | BMC Microbiology; v. 16, APR 12 2016. |
| Web of Science Citations: | 6 |
| Abstract | |
Background: As bacterial cells enter stationary phase, they adjust their growth rate to comply with nutrient restriction and acquire increased resistance to several stresses. These events are regulated by controlling gene expression at this phase, changing the mode of exponential growth into that of growth arrest, and increasing the expression of proteins involved in stress resistance. The two-component system SpdR/SpdS is required for the activation of transcription of the Caulobacter crescentus cspD gene at the onset of stationary phase. Results: In this work, we showed that both SpdR and SpdS are also induced upon entry into stationary phase, and this induction is partly mediated by ppGpp and it is not auto-regulated. Global transcriptional analysis at early stationary phase of a spdR null mutant strain compared to the wild type strain was carried out by DNA microarray. Twenty-three genes showed at least twofold decreased expression in the spdR deletion mutant strain relative to its parental strain, including cspD, while five genes showed increased expression in the mutant. The expression of a set of nine genes was evaluated by quantitative real time PCR, validating the microarray data, and indicating an important role for SpdR at stationary phase. Several of the differentially expressed genes can be involved in modulating gene expression, including four transcriptional regulators, and the RNA regulatory protein Hfq. The ribosomal proteins NusE and NusG, which also have additional regulatory functions in transcription and translation, were also downregulated in the spdR mutant, as well as the ParE1 toxin. The purified SpdR protein was shown to bind to the regulatory region of CC0517 by Electrophoretic Mobility Shift Assay, and the SpdR-regulated gene CC0731 was shown to be expressed at a lower level in the null cspD mutant, suggesting that at least part of the effect of SpdR on the expression of this gene is indirect. Conclusions: The results indicate that SpdR regulates several genes encoding proteins of regulatory function, which in turn may be required for the expression of other genes important for the transition to stationary phase. (AU) | |
| FAPESP's process: | 14/04046-8 - Regulatory networks of bacterial stress response |
| Grantee: | Marilis Do Valle Marques |
| Support type: | Research Projects - Thematic Grants |
| FAPESP's process: | 12/10563-0 - Physiology and regulation of bacterial stress response |
| Grantee: | Marilis Do Valle Marques |
| Support type: | Regular Research Grants |
| FAPESP's process: | 11/18847-4 - Identification of genes regulated in response to zinc starvation in Caulobacter crescentus |
| Grantee: | Ricardo Ruiz Mazzon |
| Support type: | Scholarships in Brazil - Post-Doctorate |
| FAPESP's process: | 11/17513-5 - Determination of genes regulated by the transcription factor SpdR and its involvement on stationary phase adaptation in Caulobacter crescentus |
| Grantee: | Carolina Antunes Do Prado Tavares da Silva |
| Support type: | Scholarships in Brazil - Post-Doctorate |