Defect in peroxisomal multifunctional enzyme MFE1 affects cAMP relay in Dictyostelium.
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.
Matsuoka
Satomi
S
Department of Biology, Graduate School of Science, Osaka University, 1-16 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
Kuwayama
Hidekazu
H
Ikeno
Daisuke
D
Oyama
Masakazu
M
Maeda
Mineko
M
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
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