title: Defect in peroxisomal multifunctional enzyme MFE1 affects cAMP relay in Dictyostelium.
abstract: We have previously reported that cells of Dictyostelium discoideum lacking the fatty acid oxidation enzyme MFE1 accumulate excess cyclopropane fatty acids from ingested bacteria. Cells in which mfeA(-) is disrupted fail to develop when grown in association with bacteria but form normal fruiting bodies when grown in axenic media. Bacterially grown mfeA(-) cells express the genes for the cyclic AMP (cAMP) receptor (carA) and adenylyl cyclase (acaA) but fail to respond to a cAMP pulse by synthesis of additional cAMP which normally relays the signal. Moreover, they do not accumulate the adhesion protein, gp80, which is encoded by the cAMP-induced gene, csaA. As a consequence, they do not acquire developmentally regulated EDTA-resistant cell-cell adhesion. When mutant cells are mixed with wild-type cells and allowed to develop together, they co-aggregate and differentiate into both spores and stalk cells. Thus, most of the developmental consequences of excess cyclopropane fatty acids appear to result from impaired cAMP relay.
authors.affiliation: Department of Biology, Graduate School of Science, Osaka University, 1-16 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Matsuoka
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Kuwayama
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ikeno
authors.forename: Masakazu
authors.initials: M
authors.lastname: Oyama
authors.forename: Mineko
authors.initials: M
authors.lastname: Maeda
mesh_terms: D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D000242:Cyclic AMP / Q000378:metabolism*; D003521:Cyclopropanes / Q000378:metabolism; D004023:Dictyostelium / Q000235:genetics / Q000502:physiology*; D005227:Fatty Acids / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D017125:Genes, Protozoan / Q000235:genetics; D009024:Morphogenesis / Q000235:genetics / Q000502:physiology; D009097:Multienzyme Complexes / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D020675:Peroxisomes / Q000235:genetics / Q000378:metabolism*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D011953:Receptors, Cyclic AMP / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
chemical_list: D015815:Cell Adhesion Molecules; D003521:Cyclopropanes; D005227:Fatty Acids; D009097:Multienzyme Complexes; D015800:Protozoan Proteins; D011953:Receptors, Cyclic AMP; C052291:cell cohesion molecule, Dictyostelium; C028775:cyclopropane fatty acids; D000242:Cyclic AMP; D000262:Adenylyl Cyclases