Premium
The alternative sigma factor SigF is a key player in the control of secretion mechanisms in Synechocystis sp. PCC 6803
Author(s) -
Flores Carlos,
Santos Marina,
Pereira Sara B.,
Mota Rita,
Rossi Federico,
De Philippis Roberto,
Couto Narciso,
Karunakaran Esther,
Wright Phillip C.,
Oliveira Paulo,
Tamagnini Paula
Publication year - 2019
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 - 10.1111/1462-2920.14465
Subject(s) - biology , secretion , synechocystis , cell envelope , microbiology and biotechnology , bacterial outer membrane , sigma factor , biochemistry , in silico , escherichia coli , gene , mutant , rna polymerase
Summary Cyanobacterial alternative sigma factors are crucial players in environmental adaptation processes, which may involve bacterial responses related to maintenance of cell envelope and control of secretion pathways. Here, we show that the Group 3 alternative sigma factor F (SigF) plays a pleiotropic role in Synechocystis sp. PCC 6803 physiology, with a major impact on growth and secretion mechanisms, such as the production of extracellular polysaccharides, vesiculation and protein secretion. Although Δ sigF growth was significantly impaired, the production of released polysaccharides (RPS) increased threefold to fourfold compared with the wild‐type. Δ sigF exhibits also impairment in formation of outer‐membrane vesicles (OMVs) and pili, as well as several other cell envelope alterations. Similarly, the exoproteome composition of Δ sigF differs from the wild‐type both in amount and type of proteins identified. Quantitative proteomics (iTRAQ) and an in silico analysis of SigF binding motifs revealed possible targets/pathways under SigF control. Besides changes in protein levels involved in secretion mechanisms, our results indicated that photosynthesis, central carbon metabolism and protein folding/degradation mechanisms are altered in Δ sigF . Overall, this work provided new evidences about the role of SigF on Synechocystis physiology and associates this regulatory element with classical and non‐classical secretion pathways.