title: The FeoC protein leads to high cellular levels of the Fe(II) transporter FeoB by preventing FtsH protease regulation of FeoB in Salmonella enterica.
abstract: In the gammaproteobacteria, the FeoA, FeoB, and FeoC proteins constitute the Feo system, which mediates ferrous iron [Fe(II)] import. Of these Feo proteins, FeoB is an inner membrane Fe(II) transporter that is aided by the small protein FeoA. However, the role of another small protein, FeoC, has remained unknown. Here we report that the FeoC protein is necessary for FeoB protein-mediated Fe(II) uptake in Salmonella experiencing low levels of oxygen and iron. The FeoC protein was found to directly bind to the FeoB transporter, leading to high cellular levels of FeoB. Depletion of the FtsH protease enabled high levels of FeoB in the absence of FeoC, suggesting that the FeoC protein protects the FeoB transporter from FtsH-mediated proteolysis. Our present study provides a singular example of bacteria that can control expression of iron uptake systems posttranslationally by employing a small iron transporter-binding protein.
authors.affiliation: Division of Microbiology, Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, South Korea.
authors.forename: Hyunkeun
authors.initials: H
authors.lastname: Kim
authors.forename: Hwiseop
authors.initials: H
authors.lastname: Lee
authors.forename: Dongwoo
authors.initials: D
authors.lastname: Shin
mesh_terms: D049069:ATP-Dependent Proteases / Q000037:antagonists & inhibitors*; D027682:Cation Transport Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D027682:Cation Transport Proteins; D014157:Transcription Factors; D007501:Iron; D049069:ATP-Dependent Proteases