Physiological roles of sigma factor SigD in Corynebacterium glutamicum

0477066 - MBÚ 2018 RIV GB eng J - Journal Article
Taniguchi, H. - Busche, T. - Patschkowski, T. - Niehaus, K. - Pátek, Miroslav - Kalinowski, J. - Wendisch, V.F.
Physiological roles of sigma factor SigD in Corynebacterium glutamicum.
BMC Microbiology. Roč. 17, č. 158 (2017), s. 158. ISSN 1471-2180. E-ISSN 1471-2180
R&D Projects: GA ČR(CZ) GA17-06991S
Institutional support: RVO:61388971
Keywords : Corynebacterium glutamicum * Sigma factor * SigD
OECD category: Microbiology
Impact factor: 2.829, year: 2017

Background: Sigma factors are one of the components of RNA polymerase holoenzymes, and an essential factor of transcription initiation in bacteria. Corynebacterium glutamicum possesses seven genes coding for sigma factors, most of which have been studied to some detail, however, the role of SigD in transcriptional regulation in C. glutamicum has been mostly unknown.
Results: In this work, pleiotropic effects of sigD overexpression at the level of phenotype, transcripts, proteins and metabolites were investigated. Overexpression of sigD decreased the growth rate of C. glutamicum cultures, and induced several physiological effects such as reduced culture foaming, turbid supernatant and cell aggregation. Upon overexpression of sigD, the level of Cmt1 (corynomycolyl transferase) in the supernatant was notably enhanced, and carbohydrate-containing compounds were excreted to the supernatant. The real-time PCR analysis revealed that sigD overexpression increased the expression of genes related to corynomycolic acid synthesis (fadD2, pks), genes encoding corynomycolyl transferases (cop1, cmt1, cmt2, cmt3), L, D-transpeptidase (lppS), a subunit of the major cell wall channel (porH), and the envelope lipid regulation factor (elrF). Furthermore, overexpression of sigD resulted in trehalose dicorynomycolate accumulation in the cell envelope.
Conclusions: This study demonstrated that SigD regulates the synthesis of corynomycolate and related compounds, and expanded the knowledge of regulatory functions of sigma factors in C. glutamicum.
Permanent Link: http://hdl.handle.net/11104/0273467