title: Choline transport in Fusarium graminearum A 3/5.
abstract: Fusarium graminearum A 3/5 possesses a high affinity system (Km = 32 +/- 8 microM; mean +/- SE) for uptake of choline, which was shown to be energy-dependent and constitutive. The maximum rate of choline uptake by this system was repressed by ammonia and glucose, showing a three-fold increase in maximum activity after nitrogen (2 h) or carbon (4 h) starvation. The system was highly specific for choline with only dimethylethanolamine (Ki = 198 +/- 29 microM), betaine aldehyde (Ki = 95 +/- 14 microM) and chlorocholine (Ki = 352 +/- 40 microM) acting as competitive inhibitors. Hemicholinium-3 acted as a mixed (non-competitive) inhibitor (KIES = 1.9 +/- 0.6 microM; KIE = 3.6 +/- 1.9 microM).
authors.affiliation: Department of Cell and Structural Biology, School of Biological Sciences, University of Manchester, UK.
authors.forename: G D
authors.initials: GD
authors.lastname: Robson
authors.forename: L C
authors.initials: LC
authors.lastname: Best
authors.forename: M G
authors.initials: MG
authors.lastname: Wiebe
authors.forename: A P
authors.initials: AP
authors.lastname: Trinci
mesh_terms: D001693:Biological Transport, Active / Q000187:drug effects; D002794:Choline / Q000031:analogs & derivatives / Q000378:metabolism*; D005670:Fusarium / Q000378:metabolism*; D006426:Hemicholinium 3 / Q000378:metabolism; D007700:Kinetics; D009584:Nitrogen / Q000172:deficiency; D000644:Quaternary Ammonium Compounds / Q000378:metabolism
chemical_list: D000644:Quaternary Ammonium Compounds; D006426:Hemicholinium 3; D009584:Nitrogen; D002794:Choline