title: Requirement of Phosphoinositides Containing Stearic Acid To Control Cell Polarity.
abstract: Phosphoinositides (PIPs) are present in very small amounts but are essential for cell signaling, morphogenesis, and polarity. By mass spectrometry, we demonstrated that some PIPs with stearic acyl chains were strongly disturbed in a psi1Δ Saccharomyces cerevisiae yeast strain deficient in the specific incorporation of a stearoyl chain at the sn-1 position of phosphatidylinositol. The absence of PIPs containing stearic acid induced disturbances in intracellular trafficking, although the total amount of PIPs was not diminished. Changes in PIPs also induced alterations in the budding pattern and defects in actin cytoskeleton organization (cables and patches). Moreover, when the PSI1 gene was impaired, a high proportion of cells with bipolar cortical actin patches that occurred concomitantly with the bipolar localization of Cdc42p was specifically found among diploid cells. This bipolar cortical actin phenotype, never previously described, was also detected in a bud9Δ/bud9Δ strain. Very interestingly, overexpression of PSI1 reversed this phenotype.
authors.affiliation: Université Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France francois.doignon@u-bordeaux.fr.
authors.forename: François
authors.initials: F
authors.lastname: Doignon
authors.affiliation: Université Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Laquel
authors.affiliation: Université Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Testet
authors.affiliation: Université Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Tuphile
authors.affiliation: Université Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France Metabolome Facility of Bordeaux, Functional Genomics Center, Villenave d'Ornon, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Fouillen
authors.affiliation: Université Bordeaux, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, Bordeaux, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Bessoule
mesh_terms: D000199:Actins / Q000378:metabolism / Q000648:ultrastructure; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D016764:Cell Polarity; D017353:Gene Deletion; D010716:Phosphatidylinositols / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013229:Stearic Acids / Q000032:analysis / Q000378:metabolism*
chemical_list: D000199:Actins; D010716:Phosphatidylinositols; D029701:Saccharomyces cerevisiae Proteins; D013229:Stearic Acids; C031183:stearic acid; D000217:Acyltransferases; C553235:Cst26 protein, S cerevisiae