title: Phosphatidylinositol 4-kinases are required for autophagic membrane trafficking.
abstract: Macroautophagy (hereafter autophagy) is a degradative cellular pathway that protects eukaryotic cells from stress, starvation, and microbial infection. This process must be tightly controlled because too little or too much autophagy can be deleterious to cellular physiology. The phosphatidylinositol (PtdIns) 3-kinase Vps34 is a lipid kinase that regulates autophagy, but the role of other PtdIns kinases has not been examined. Here we demonstrate a role for PtdIns 4-kinases and PtdIns4P 5-kinases in selective and nonselective types of autophagy in yeast. The PtdIns 4-kinase Pik1 is involved in Atg9 trafficking through the Golgi and is involved in both nonselective and selective types of autophagy, whereas the PtdIns4P 5-kinase Mss4 is specifically involved in mitophagy but not nonselective autophagy. Our data indicate that phosphoinositide kinases have multiple roles in the regulation of autophagic pathways.
authors.affiliation: Life Sciences Institute and Department of Molecular, University of Michigan, Ann Arbor, Michigan 48109-2216, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.forename: Zhifen
authors.initials: Z
authors.lastname: Yang
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.forename: Kai
authors.initials: K
authors.lastname: Mao
authors.forename: Usha
authors.initials: U
authors.lastname: Nair
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Klionsky
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase / Q000235:genetics / Q000378:metabolism*; D001343:Autophagy; D000071183:Autophagy-Related Proteins; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009154:Mutation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C434065:ATG9 protein, S cerevisiae; D000071183:Autophagy-Related Proteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); D019870:1-Phosphatidylinositol 4-Kinase; C441760:PIK1 protein, S cerevisiae; C112465:STT4 protein, S cerevisiae; C489795:MSS4 protein, S cerevisiae