title: The C-terminal region of the RNA helicase CshA is required for the interaction with the degradosome and turnover of bulk RNA in the opportunistic pathogen Staphylococcus aureus.
abstract: Staphylococcus aureus is a versatile opportunistic pathogen that adapts readily to a variety of different growth conditions. This adaptation requires a rapid regulation of gene expression including the control of mRNA abundance. The CshA DEAD-box RNA helicase was previously shown to be required for efficient turnover of the agr quorum sensing mRNA. Here we show by transcriptome-wide RNA sequencing and microarray analyses that CshA is required for the degradation of bulk mRNA. Moreover a subset of mRNAs is significantly stabilised in absence of CshA. Deletion of the C-terminal extension affects RNA turnover similar to the full deletion of the cshA gene. In accordance with RNA decay data, the C-terminal region of CshA is required for an RNA-independent interaction with components of the RNA degradation machinery. The C-terminal truncation of CshA reduces its ATPase activity and this reduction cannot be compensated at high RNA concentrations. Finally, the deletion of the C-terminal extension does affect growth at low temperatures, but to a significantly lesser degree than the full deletion, indicating that the core of the helicase can assume a partial function and opening the possibility that CshA is involved in different cellular processes.
authors.affiliation: a Department of Microbiology and Molecular Medicine ; Medical Faculty; University of Geneva ; Michel Servet , Geneva , Switzerland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Giraud
authors.forename: Stéphane
authors.initials: S
authors.lastname: Hausmann
authors.forename: Sylvain
authors.initials: S
authors.lastname: Lemeille
authors.forename: Julien
authors.initials: J
authors.lastname: Prados
authors.forename: Peter
authors.initials: P
authors.lastname: Redder
authors.forename: Patrick
authors.initials: P
authors.lastname: Linder
mesh_terms: D004722:Endoribonucleases / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D011117:Polyribonucleotide Nucleotidyltransferase / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000201:enzymology / Q000378:metabolism*
chemical_list: D009097:Multienzyme Complexes; D012333:RNA, Messenger; C111244:degradosome; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases; D020365:RNA Helicases
keywords: CshA; DEAD-box family; RNA decay; RNase; degradosome