title: IPT1-independent sphingolipid biosynthesis and yeast inhibition by syringomycin E and plant defensin DmAMP1.
abstract: Both bacterial cyclic lipodepsipeptide syringomycin E and plant defensin DmAMP1 were shown previously to require expression of the yeast gene IPT1 for fungicidal action against Saccharomyces cerevisiae. IPT1 encodes a sphingolipid biosynthetic pathway glycotransferase that produces the terminal sphingolipid mannosyldiinositolphosphoceramide. However, when grown in half-strength potato dextrose medium, an ipt1 deletion mutant of S. cerevisiae was observed to be sensitive to syringomycin E and DmAMP1 and to produce small amounts of mannosyldiinositolphosphoceramide. These results show that the terminal sphingolipid but not IPT1 expression is required for fungicidal activity, and they suggest an IPT1-independent route for mannosyldiinositolphosphoceramide biosynthesis.
authors.affiliation: Department of Biology, Utah State University, Logan 84322-5305, USA.
authors.forename: Yang Ju
authors.initials: YJ
authors.lastname: Im
authors.forename: Jolanta
authors.initials: J
authors.lastname: Idkowiak-Baldys
authors.forename: Karin
authors.initials: K
authors.lastname: Thevissen
authors.forename: Bruno P A
authors.initials: BP
authors.lastname: Cammue
authors.forename: Jon Y
authors.initials: JY
authors.lastname: Takemoto
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology; D003470:Culture Media / Q000494:pharmacology; D023082:Defensins; D010456:Peptides, Cyclic / Q000494:pharmacology*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D010940:Plant Proteins / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000201:enzymology* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D013107:Sphingolipids / Q000096:biosynthesis*
chemical_list: D023181:Antimicrobial Cationic Peptides; D003470:Culture Media; D023082:Defensins; C099969:Dm-AMP1 protein, Dahlia merckii; D010456:Peptides, Cyclic; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins; D013107:Sphingolipids; C105246:syringomycin E; C109311:IPT1 protein, S cerevisiae; D017853:Phosphotransferases (Alcohol Group Acceptor)