Format

Send to

Choose Destination
EMBO J. 2000 Nov 1;19(21):5782-92.

Osmotic stress response in Dictyostelium is mediated by cAMP.

Author information

1
Max-Planck-Institut für Biochemie, D-82152 Martinsried, Germany.

Abstract

DokA, a homolog of bacterial hybrid histidine kinases, is essential for hyperosmotic stress resistance in Dictyostelium: We show that a transient intracellular cAMP signal, dependent on the presence of DokA, is generated in response to an osmotic shock. This variation of cAMP levels contributes to survival under hypertonic conditions. In contrast to the low cAMP levels observed in dokA(-) strains, overexpression of the receiver domain of DokA causes an increase in cAMP levels, resulting in a rapidly developing phenotype. We present biochemical and cell biological data indicating that the DokA receiver domain is a dominant-negative regulator of a phosphorelay, which controls the intracellular cAMP phosphodiesterase RegA. The activity of the DokA receiver domain depends on a conserved aspartate, mutation of which reverses the developmental phenotype, as well as the deregulation of cAMP metabolism.

PMID:
11060029
PMCID:
PMC305785
DOI:
10.1093/emboj/19.21.5782
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center