title: Macromitophagy, neutral lipids synthesis, and peroxisomal fatty acid oxidation protect yeast from "liponecrosis", a previously unknown form of programmed cell death.
abstract: We identified a form of cell death called "liponecrosis." It can be elicited by an exposure of the yeast Saccharomyces cerevisiae to exogenous palmitoleic acid (POA). Our data imply that liponecrosis is: (1) a programmed, regulated form of cell death rather than an accidental, unregulated cellular process and (2) an age-related form of cell death. Cells committed to liponecrotic death: (1) do not exhibit features characteristic of apoptotic cell death; (2) do not display plasma membrane rupture, a hallmark of programmed necrotic cell death; (3) akin to cells committed to necrotic cell death, exhibit an increased permeability of the plasma membrane for propidium iodide; (4) do not display excessive cytoplasmic vacuolization, a hallmark of autophagic cell death; (5) akin to cells committed to autophagic death, exhibit a non-selective en masse degradation of cellular organelles and require the cytosolic serine/threonine protein kinase Atg1p for executing the death program; and (6) display a hallmark feature that has not been reported for any of the currently known cell death modalities-namely, an excessive accumulation of lipid droplets where non-esterified fatty acids (including POA) are deposited in the form of neutral lipids. We therefore concluded that liponecrotic cell death subroutine differs from the currently known subroutines of programmed cell death. Our data suggest a hypothesis that liponecrosis is a cell death module dynamically integrated into a so-called programmed cell death network, which also includes the apoptotic, necrotic, and autophagic modules of programmed cell death. Based on our findings, we propose a mechanism underlying liponecrosis.
authors.affiliation: Department of Anatomy and Cell Biology; McGill University; Montreal, Quebec, Canada; Department of Chemistry and Chemical Engineering; Royal Military College of Canada; Kingston, Ontario, Canada.
authors.forename: Sara
authors.initials: S
authors.lastname: Sheibani
authors.affiliation: Department of Biology; Concordia University; Montreal, Quebec, Canada.
authors.forename: Vincent R
authors.initials: VR
authors.lastname: Richard
authors.affiliation: Department of Biology; Concordia University; Montreal, Quebec, Canada.
authors.forename: Adam
authors.initials: A
authors.lastname: Beach
authors.affiliation: Department of Biology; Concordia University; Montreal, Quebec, Canada.
authors.forename: Anna
authors.initials: A
authors.lastname: Leonov
authors.affiliation: Department of Biology; Concordia University; Montreal, Quebec, Canada.
authors.forename: Rachel
authors.initials: R
authors.lastname: Feldman
authors.affiliation: Department of Biology; Concordia University; Montreal, Quebec, Canada.
authors.forename: Sevan
authors.initials: S
authors.lastname: Mattie
authors.affiliation: Department of Biology; Concordia University; Montreal, Quebec, Canada.
authors.forename: Leila
authors.initials: L
authors.lastname: Khelghatybana
authors.affiliation: Department of Biology; Concordia University; Montreal, Quebec, Canada.
authors.forename: Amanda
authors.initials: A
authors.lastname: Piano
authors.affiliation: Department of Chemistry and Chemical Engineering; Royal Military College of Canada; Kingston, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Greenwood
authors.affiliation: Department of Anatomy and Cell Biology; McGill University; Montreal, Quebec, Canada.
authors.forename: Hojatollah
authors.initials: H
authors.lastname: Vali
authors.affiliation: Department of Biology; Concordia University; Montreal, Quebec, Canada.
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Titorenko
mesh_terms: D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000102:Acetyl-CoA C-Acyltransferase / Q000235:genetics / Q000378:metabolism; D019748:Carbon-Carbon Double Bond Isomerases / Q000235:genetics / Q000378:metabolism; D016923:Cell Death / Q000235:genetics*; D004746:Enoyl-CoA Hydratase / Q000235:genetics / Q000378:metabolism; D008055:Lipids / Q000096:biosynthesis / Q000737:chemistry; D063306:Mitophagy / Q000235:genetics*; D009336:Necrosis / Q000235:genetics*; D020675:Peroxisomes / Q000235:genetics / Q000378:metabolism; D019998:Racemases and Epimerases / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development
chemical_list: D008055:Lipids; C038784:fatty acid oxidation complex; D015094:3-Hydroxyacyl CoA Dehydrogenases; D000102:Acetyl-CoA C-Acyltransferase; D004746:Enoyl-CoA Hydratase; D019998:Racemases and Epimerases; D019748:Carbon-Carbon Double Bond Isomerases
keywords: apoptosis; autophagic cell death; autophagy; fatty acids; lipid droplets; mechanisms of programmed cell death; mitophagy; necrosis; peroxisomes; yeast