title: Regulation and function of G alpha protein subunits in Dictyostelium.
abstract: We have examined the developmental regulation and function of two G alpha protein subunits, G alpha 1 and G alpha 2, from Dictyostelium. G alpha 1 is expressed in vegetative cells through aggregate stages while G alpha 2 is inducible by cAMP pulses and preferentially expressed in aggregation. Our results suggest that G alpha 2 encodes the G alpha protein subunit associated with the cAMP receptor and mediates all known receptor-activated intracellular signal transduction processes, including chemotaxis and gene regulation. G alpha 1 appears to function in both the cell cycle and development. Overexpression of G alpha 1 results in large, multinucleated cells that develop abnormally. The central role that these G alpha proteins play in signal transduction processes and in controlling Dictyostelium development is discussed.
authors.affiliation: Department of Biology, University of California, San Diego, La Jolla 92093.
authors.forename: A
authors.initials: A
authors.lastname: Kumagai
authors.forename: M
authors.initials: M
authors.lastname: Pupillo
authors.forename: R
authors.initials: R
authors.lastname: Gundersen
authors.forename: R
authors.initials: R
authors.lastname: Miake-Lye
authors.forename: P N
authors.initials: PN
authors.lastname: Devreotes
authors.forename: R A
authors.initials: RA
authors.lastname: Firtel
mesh_terms: D002872:Chromosome Deletion; D000242:Cyclic AMP / Q000494:pharmacology; D004023:Dictyostelium / Q000254:growth & development* / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D005800:Genes, Fungal; D009154:Mutation; D012331:RNA, Fungal / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D012331:RNA, Fungal; D012333:RNA, Messenger; D000242:Cyclic AMP; D019204:GTP-Binding Proteins