Targeting of two signal transduction pathways to different regions of the bacterial cell.
Components of bacterial chemosensory pathways which sense via transmembrane receptors have been shown to localize to the cell poles. Many species, however, have operons encoding multiple putative chemosensory pathways, some including putative cytoplasmic receptors. In-genome fusions to single or multiple genes encoding components of two chemosensory pathways in Rhodobacter sphaeroides, cheOp2 and cheOp3, revealed that while sensory transducing proteins associated with transmembrane receptors and encoded on cheOp2 were targeted to the cell poles, the proteins associated with putative cytoplasmic receptors and encoded on cheOp3 were all targeted to a cytoplasmic cluster. No proteins were localized to both sites. These data show that bacteria target components of related pathways to different sites in the cell, presumably preventing direct cross-talk between the different pathways, but allowing a balanced response between extracellular and cytoplasmic signals. It also indicates that there is intracellular organization in bacterial cells, with specific proteins targeted and localized to cytoplasmic regions.
Wadhams
G H
GH
Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, United Kingdom.
Warren
A V
AV
Martin
A C
AC
Armitage
J P
JP
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002633:Chemotaxis / Q000502:physiology; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D000072236:Methyl-Accepting Chemotaxis Proteins; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D008854:Microscopy, Electron / Q000379:methods; D009876:Operon; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012242:Rhodobacter sphaeroides / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
D001426:Bacterial Proteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D011993:Recombinant Fusion Proteins; C054562:yellow fluorescent protein, Bacteria; C051236:CheW protein, Bacteria; C069656:CheB protein, Bacteria; D008780:Methyltransferases; C038706:chemotaxis methyltransferase