RRC ID 36542
Author Araki T, Tsujioka M, Abe T, Fukuzawa M, Meima M, Schaap P, Morio T, Urushihara H, Katoh M, Maeda M, Tanaka Y, Takeuchi I, Williams JG.
Title A STAT-regulated, stress-induced signalling pathway in Dictyostelium.
Journal J Cell Sci
Abstract The Dictyostelium stalk cell inducer differentiation-inducing factor (DIF) directs tyrosine phosphorylation and nuclear accumulation of the STAT (signal transducer and activator of transcription) protein Dd-STATc. We show that hyperosmotic stress, heat shock and oxidative stress also activate Dd-STATc. Hyperosmotic stress is known to elevate intracellular cGMP and cAMP levels, and the membrane-permeant analogue 8-bromo-cGMP rapidly activates Dd-STATc, whereas 8-bromo-cAMP is a much less effective inducer. Surprisingly, however, Dd-STATc remains stress activatable in null mutants for components of the known cGMP-mediated and cAMP-mediated stress-response pathways and in a double mutant affecting both pathways. Also, Dd-STATc null cells are not abnormally sensitive to hyperosmotic stress. Microarray analysis identified two genes, gapA and rtoA, that are induced by hyperosmotic stress. Osmotic stress induction of gapA and rtoA is entirely dependent on Dd-STATc. Neither gene is inducible by DIF but both are rapidly inducible with 8-bromo-cGMP. Again, 8-bromo-cAMP is a much less potent inducer than 8-bromo-cGMP. These data show that Dd-STATc functions as a transcriptional activator in a stress-response pathway and the pharmacological evidence, at least, is consistent with cGMP acting as a second messenger.
Volume 116(Pt 14)
Pages 2907-15
Published 2003-7-15
DOI 10.1242/jcs.00501
PII jcs.00501
PMID 12771188
MeSH Active Transport, Cell Nucleus Animals Blotting, Northern Blotting, Western Cell Cycle Proteins / metabolism Cell Nucleus / metabolism Cyclic AMP / metabolism Cyclic GMP / analogs & derivatives* Cyclic GMP / metabolism Dictyostelium / metabolism* Dose-Response Relationship, Drug Green Fluorescent Proteins Immunohistochemistry Luminescent Proteins / metabolism Models, Biological Mutation Oligonucleotide Array Sequence Analysis Osmosis Oxidative Stress Phosphorylation Protein Transport Protozoan Proteins / metabolism Protozoan Proteins / physiology* STAT Transcription Factors Signal Transduction* Time Factors Trans-Activators / metabolism Trans-Activators / physiology* Transcription, Genetic Tyrosine / metabolism
IF 4.573
Times Cited 34
Cellular slime molds