RcsF is an outer membrane lipoprotein involved in the RcsCDB phosphorelay signaling pathway in Escherichia coli.
The RcsCDB signal transduction system is an atypical His-Asp phosphorelay conserved in gamma-proteobacteria. Besides the three proteins directly involved in the phosphorelay, two proteins modulate the activity of the system. One is RcsA, which can stimulate the activity of the response regulator RcsB independently of the phosphorelay to regulate a subset of RcsB targets. The other is RcsF, a putative outer membrane lipoprotein mediating the signaling to the sensor RcsC. How RcsF transduces the signal to RcsC is unknown. Although the molecular and physiological signals remain to be identified, the common feature among the reported Rcs-activating conditions is perturbation of the envelope. As an initial step to explore the RcsF-RcsC functional relationship, we demonstrate that RcsF is an outer membrane lipoprotein oriented towards the periplasm. We also report that a null mutation in surA, a gene required for correct folding of periplasmic proteins, activates the Rcs pathway through RcsF. In contrast, activation of this pathway by overproduction of the membrane chaperone-like protein DjlA does not require RcsF. Conversely, activation of the pathway by RcsF overproduction does not require DjlA either, indicating the existence of two independent signaling pathways toward RcsC.
Castanié-Cornet
Marie-Pierre
MP
Institut de Génétique et de Microbiologie, UMR 8621, Centre National de la Recherche Scientifique and Université Paris-Sud, Bâtiment 400, 91 405 Orsay cedex, France.
Cam
Kaymeuang
K
Jacq
Annick
A
D000595:Amino Acid Sequence; D016667:Bacterial Capsules / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins; D003545:Cysteine; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000378:metabolism*; D019696:Peptidylprolyl Isomerase; D019897:Periplasm / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010770:Phosphotransferases / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D012694:Serine; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*
D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; C489568:RcsB protein, E coli; D014157:Transcription Factors; C489728:rcsC protein, E coli; C078611:rcsF protein, E coli; D012694:Serine; D010770:Phosphotransferases; D011494:Protein Kinases; C434271:rcsD protein, E coli; D010749:Phosphoprotein Phosphatases; C490900:SurA protein, E coli; D019696:Peptidylprolyl Isomerase; D003545:Cysteine