title: SlyA regulates type III secretion system (T3SS) genes in parallel with the T3SS master regulator HrpL in Dickeya dadantii 3937.
abstract: The hypersensitive response and pathogenicity (hrp) genes of Dickeya dadantii 3937 encode a type III secretion system (T3SS) which is essential for its full virulence. Previous studies of the T3SS regulation in D. dadantii 3937 revealed that the expression of the hrp genes is regulated by a master regulator, HrpL, through the HrpX-HrpY-HrpS-HrpL and GacS-GacA-rsmB-RsmA pathways. In this work, we identified a novel regulator of the SlyA/MarR family, SlyA, which regulates hrp genes of the HrpL regulon in parallel with HrpL in D. dadantii. SlyA regulates the T3SS in a two-tier manner. It negatively regulates the expression of hrpL by downregulating hrpS and upregulating rsmA. Interestingly, concomitant with its downregulation of the hrpL, SlyA positively regulates the expression of hrpA and hrpN, two hrp genes located in the HrpL regulon. In contrast to Pectobacterium carotovorum, the expression of slyA is not controlled by ExpR and ExpI in D. dadantii 3937. We further show that SlyA is involved in controlling swimming motility and pellicle formation in D. dadantii 3937.
authors.affiliation: Department of Biological Sciences, University of Wisconsin, Milwaukee, Wisconsin, USA.
authors.forename: Lifang
authors.initials: L
authors.lastname: Zou
authors.forename: Quan
authors.initials: Q
authors.lastname: Zeng
authors.forename: Haiping
authors.initials: H
authors.lastname: Lin
authors.forename: Prasad
authors.initials: P
authors.lastname: Gyaneshwar
authors.forename: Gongyou
authors.initials: G
authors.lastname: Chen
authors.forename: Ching-Hong
authors.initials: CH
authors.lastname: Yang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D004755:Enterobacteriaceae / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D008124:Locomotion; D021381:Protein Transport; D018085:Regulon; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D037521:Virulence Factors