Interacting signaling pathways controlling multicellular development in Dictyostelium.
cAMP functions as the key extracellular signaling molecule controlling Dictyostelium development acting through classic G-protein-coupled/serpentine receptors. Whereas aggregation is controlled by nanomolar pulses of cAMP, a more continuous micromolar signal controls multicellular differentiation by activating a transcriptional cascade via a receptor-mediated but non G-protein-coupled pathway. Potential mechanisms by which extracellular cAMP functions to differentially control aggregation followed by morphogenesis and cell-type differentiation are discussed. This review also summarizes new findings elucidating pathways controlling cell-type regulation in this organism, including signaling cascades mediated by glycogen synthase kinase 3 and cAMP-dependent protein kinase, key regulators of cell-type differentiation in metazoans, and newly identified transcription factors.
Firtel
R A
RA
Department of Biology, Center for Molecular Genetics, University of California at San Diego, La Jolla 92093-0634, USA. rafirtel@ucsd.edu
D000818:Animals; D002455:Cell Division; D000242:Cyclic AMP / Q000502:physiology*; D004023:Dictyostelium / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005801:Genes, Homeobox; D008954:Models, Biological; D011494:Protein Kinases / Q000378:metabolism; D015398:Signal Transduction; D013172:Spores, Fungal; D014157:Transcription Factors / Q000378:metabolism; D016335:Zinc Fingers
D014157:Transcription Factors; D000242:Cyclic AMP; D011494:Protein Kinases; D019204:GTP-Binding Proteins