title: Change in activity of serine palmitoyltransferase affects sensitivity to syringomycin E in yeast Saccharomyces cerevisiae.
abstract: Syringomycin E is a cyclic lipodepsipeptide produced by strains of the plant bacterium Pseudomonas syringae pv. syringae. Genetic studies involving the yeast Saccharomyces cerevisiae have revealed that complex sphingolipids play important roles in the action of syringomycin E. Here, we found a novel mutation that confers resistance to syringomycin E on yeast; that is, a deletion mutant of ORM1 and ORM2, which encode negative regulators of serine palmitoyltransferase catalyzing the initial step of sphingolipid biosynthesis, exhibited resistance to syringomycin E. On the contrary, overexpression of Orm2 resulted in high sensitivity to the toxin. Moreover, overexpression of Lcb1 and Lcb2, catalytic subunits of serine palmitoyltransferase, causes resistance to the toxin, whereas partial repression of expression of Lcb1 had the opposite effect. Partial reduction of complex sphingolipids by repression of expression of Aur1, an inositol phosphorylceramide synthase, also resulted in high sensitivity to the toxin. These results suggested that an increase in sphingolipid biosynthesis caused by a change in the activity of serine palmitoyltransferase causes resistance to syringomycin E.
authors.affiliation: Department of Chemistry, Faculty of Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan.
authors.forename: Moeko
authors.initials: M
authors.lastname: Toume
authors.forename: Motohiro
authors.initials: M
authors.lastname: Tani
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D025141:Drug Resistance, Fungal; D017353:Gene Deletion; D015870:Gene Expression; D010456:Peptides, Cyclic / Q000494:pharmacology*; D044224:Pseudomonas syringae / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D051102:Serine C-Palmitoyltransferase / Q000235:genetics / Q000378:metabolism*; D013107:Sphingolipids / Q000096:biosynthesis
chemical_list: D000935:Antifungal Agents; C548539:Orm1 protein, S cerevisiae; C548540:Orm2 protein, S cerevisiae; D010456:Peptides, Cyclic; D029701:Saccharomyces cerevisiae Proteins; D013107:Sphingolipids; C105246:syringomycin E; C495086:LCB1 protein, S cerevisiae; C495087:LCB2 protein, S cerevisiae; D051102:Serine C-Palmitoyltransferase
keywords: Orm; Saccharomyces cerevisiae; serine palmitoyltransferase; sphingolipid; syringomycin E; toxin