Stk1-mediated phosphorylation stimulates the DNA-binding properties of the Staphylococcus aureus SpoVG transcriptional factor.
The stage V sporulation protein G (SpoVG) homolog of Staphylococcus aureus is a modulator of virulence factor synthesis and antibiotic resistance in this clinically important gram-positive pathogen. Here we demonstrate that SpoVG can be phosphorylated by the staphylococcal Ser/Thr protein kinase Stk1 and that phosphorylation positively affects its DNA-binding properties. Mass spectrometric analyses and site directed mutagenesis identified Thr4, Thr13, Thr24 and Ser41 as phospho-acceptors. Stk1-mediated phosphorylation markedly enhanced the DNA binding activity of SpoVG towards the promoter regions of target genes such as capA, lip, and nuc1. Similarly, trans-complementation of the S. aureus ΔyabJ-spoVG mutant SM148 with a SpoVG derivative that mimics constitutive phosphorylation, SpoVG_Asp, exhibited capA, lip, and nuc1 transcript levels that were comparable to the levels seen with the wild-type, whereas trans-complementation with a phosphoablative variant of SpoVG (SpoVG_Ala) produced transcript levels similar to the ones seen in SM148. Our data suggest that the expression/activity of this transcription factor is tightly controlled in S. aureus by transcriptional, post-transcriptional and post-translational mechanisms.
Institute of Medical Microbiology and Hygiene, Saarland University, Homburg, Germany.
Markus
M
Bischoff
Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier II, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
Solène
S
Brelle
Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier II, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
Sabrina
S
Minatelli
Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier II, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France. Electronic address: virginie.molle@univ-montp2.fr.
Virginie
V
Molle
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation / Q000502:physiology; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C095876:SpoVG protein, Bacillus subtilis; D014157:Transcription Factors; D037521:Virulence Factors; D017346:Protein Serine-Threonine Kinases; C546823:Stk1 protein, Staphylococcus aureus
Phosphorylation; Ser/Thr Protein Kinase; SpoVG; Staphylococcus aureus; Transcriptional regulation