title: Acetylation of the response regulator RcsB controls transcription from a small RNA promoter.
abstract: Nε-lysine acetylation was recently discovered on many bacterial proteins that function in diverse cellular processes. Thus, many questions remain unanswered. For example, what mechanisms regulate lysine acetylation? Does acetylation affect physiology? To help answer these questions, we studied the Escherichia coli response regulator and transcription factor RcsB, which is reported to be acetylated in vitro. To characterize RcsB acetylation, we monitored transcription from the rprA promoter, which requires RcsB. The conventional view is that RcsB is activated by phosphorylation through either the Rcs phosphorelay or acetyl phosphate. We affirmed that rprA transcription requires phosphorylated RcsB and showed that acetyl-phosphate (AcP) is a phosphoryl group donor to RcsB. However, a mutant that accumulates AcP (ackA) exhibited a reduction in rprA transcription instead of the predicted increase. rprA transcription also diminished in the cobB mutant, which lacks the only known E. coli protein deacetylase. This suggests the existence of an inhibitory mechanism that involves lysine acetylation, a supposition supported by the observation that RcsB isolated from the ackA or cobB mutant was hyperacetylated. Finally, we used a genetic approach to identify an AckA- and CobB-sensitive lysine (Lys-154) that controls RcsB activity. We propose that acetylation inhibits RcsB activity and that some of this inhibition acts through the acetylation of Lys-154.
authors.affiliation: Department of Microbiology and Immunology, Loyola University Chicago, Stritch School of Medicine, Maywood, IL, USA.
authors.forename: Linda I
authors.initials: LI
authors.lastname: Hu
authors.forename: Bui Khanh
authors.initials: BK
authors.lastname: Chi
authors.forename: Misty L
authors.initials: ML
authors.lastname: Kuhn
authors.forename: Ekaterina V
authors.initials: EV
authors.lastname: Filippova
authors.forename: Arti J
authors.initials: AJ
authors.lastname: Walker-Peddakotla
authors.forename: Katrin
authors.initials: K
authors.lastname: Bäsell
authors.forename: Dörte
authors.initials: D
authors.lastname: Becher
authors.forename: Wayne F
authors.initials: WF
authors.lastname: Anderson
authors.forename: Haike
authors.initials: H
authors.lastname: Antelmann
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Wolfe
mesh_terms: D000107:Acetylation; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008239:Lysine / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012313:RNA / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; C489568:RcsB protein, E coli; D014157:Transcription Factors; D012313:RNA; D008239:Lysine