Phosphate acquisition components of the Myxococcus xanthus Pho regulon are regulated by both phosphate availability and development
Whitworth, David E., Holmes, Antony B., Irvine, Alistair G., Hodgson, D. A. (David A.) and Scanlan, David J. . (2008) Phosphate acquisition components of the Myxococcus xanthus Pho regulon are regulated by both phosphate availability and development. Journal of Bacteriology, Vol.190 (No.6). pp. 1997-2003. ISSN 0021-9193Full text not available from this repository.
Official URL: http://dx.doi.org/10.1128/JB.01781-07
In many organisms, phosphatase expression and phosphate (P) uptake are coordinately regulated by the Pho regulon. In Myxococcus xanthus P limitation initiates multicellular development, a process associated with changes in phosphatase expression. We sought here to characterize the link between P acquisition and development in this bacterium, an organism capable of preying upon other microorganisms as a sole nutrient source. M. xanthus seems to possess no significant internal P stores, as reducing the P concentration to less than 10 mu M retarded growth within one doubling time. Pyrophosphate, polyphosphate, and glyceraldehyde-3-phosphate could support growth as sole P sources, although many other P-containing biomolecules could not (including nucleic acids and phospholipids). Several Pho regulon promoters were found to be highly active during vegetative growth, and P limitation specifically induced pstSCAB, ACPA1, and pho3 promoter activity and repressed pit expression. Enhanced pstSCAB and pho3 promoter activities in a phoP4 mutant (in the presence of high and low concentrations of P) suggested that PhoP4 acts as a repressor of these genes. However, in a phoP4 background, the activities of pstSCAB remained P regulated, suggesting that there is additional regulation by a P-sensitive factor. Initiation of multicellular development caused immediate downregulation of Pho regulon genes and caused pstSCAB and pho3 promoter activities to become P insensitive. Hence, P acquisition components of the M. xanthus Pho regulon are regulated by both P availability and development, with developmental down-regulation overriding up-regulation by P limitation. These observations suggest that when development is initiated, subsequent changes in P availability become irrelevant to the population, which presumably has sufficient intrinsic P to ensure completion of the developmental program.
|Item Type:||Journal Article|
|Subjects:||Q Science > QR Microbiology|
|Divisions:||Faculty of Science > Life Sciences (2010- )
Faculty of Science > Molecular Organisation and Assembly in Cells (MOAC)
|Journal or Publication Title:||Journal of Bacteriology|
|Publisher:||American Society for Microbiology|
|Number of Pages:||7|
|Page Range:||pp. 1997-2003|
|Access rights to Published version:||Restricted or Subscription Access|
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