title: Involvement of the Saccharomyces cerevisiae hydrolase Ldh1p in lipid homeostasis.
abstract: Here, we report the functional characterization of the newly identified lipid droplet hydrolase Ldh1p. Recombinant Ldh1p exhibits esterase and triacylglycerol lipase activities. Mutation of the serine in the hydrolase/lipase motif GXSXG completely abolished esterase activity. Ldh1p is required for the maintenance of a steady-state level of the nonpolar and polar lipids of lipid droplets. A characteristic feature of the Saccharomyces cerevisiae Δldh1 strain is the appearance of giant lipid droplets and an excessive accumulation of nonpolar lipids and phospholipids upon growth on medium containing oleic acid as a sole carbon source. Ldh1p is thought to play a role in maintaining the lipid homeostasis in yeast by regulating both phospholipid and nonpolar lipid levels.
authors.affiliation: Institut für Physiologische Chemie, Ruhr-Universität Bochum, Universitätsstraße 150, D-44780 Bochum, Germany.
authors.forename: Mykhaylo O
authors.initials: MO
authors.lastname: Debelyy
authors.forename: Sven
authors.initials: S
authors.lastname: Thoms
authors.forename: Melanie
authors.initials: M
authors.lastname: Connerth
authors.forename: Günther
authors.initials: G
authors.lastname: Daum
authors.forename: Ralf
authors.initials: R
authors.lastname: Erdmann
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D057075:Enzyme Assays; D004950:Esterases / Q000378:metabolism; D055786:Gene Knockout Techniques; D050356:Lipid Metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D053141:Organelle Size / Q000235:genetics; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure; D010741:Phospholipases A / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D021381:Protein Transport / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D004950:Esterases; C561125:Ldh1 protein, S cerevisiae; D010741:Phospholipases A