title: Atg28, a novel coiled-coil protein involved in autophagic degradation of peroxisomes in the methylotrophic yeast Pichia pastoris.
abstract: In methylotrophic yeasts, peroxisomes are required for methanol utilization, but are dispensable for growth on most other carbon sources. Upon adaptation of cells grown on methanol to glucose or ethanol, redundant peroxisomes are selectively and quickly shipped to, and degraded in, vacuoles via a process termed pexophagy. We identified a novel gene named ATG28 (autophagy-related genes) involved in pexophagy in the yeast Pichia pastoris. This yeast exhibits two morphologically distinct pexophagy pathways, micro- and macropexophagy, induced by glucose or ethanol, respectively. Deficiency in ATG28 impairs both pexophagic mechanisms but not general (bulk turnover) autophagy, a degradation pathway in yeast triggered by nitrogen starvation. It is known that the micro-, macropexophagy, and general autophagy machineries are distinct but share some molecular components. The identification of ATG28 suggests that pexophagy may involve species-specific components, since this gene appears to have only weak homologues in other yeasts.
authors.affiliation: Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv, Ukraine.
authors.forename: Oleh V
authors.initials: OV
authors.lastname: Stasyk
authors.forename: Olena G
authors.initials: OG
authors.lastname: Stasyk
authors.forename: Richard D
authors.initials: RD
authors.lastname: Mathewson
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Farré
authors.forename: Volodymyr Y
authors.initials: VY
authors.lastname: Nazarko
authors.forename: Olena S
authors.initials: OS
authors.lastname: Krasovska
authors.forename: Suresh
authors.initials: S
authors.lastname: Subramani
authors.forename: James M
authors.initials: JM
authors.lastname: Cregg
authors.forename: Andriy A
authors.initials: AA
authors.lastname: Sibirny
mesh_terms: D000595:Amino Acid Sequence; D001343:Autophagy / Q000235:genetics; D001483:Base Sequence; D005656:Fungal Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D005800:Genes, Fungal / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D020675:Peroxisomes / Q000378:metabolism*; D010843:Pichia / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D017422:Sequence Analysis, DNA
chemical_list: D005656:Fungal Proteins