title: Activation of phospholipase D by the small GTPase Sar1p is required to support COPII assembly and ER export.
abstract: The small GTPase Sar1p controls the assembly of the cytosolic COPII coat that mediates export from the endoplasmic reticulum (ER). Here we demonstrate that phospholipase D (PLD) activation is required to support COPII-mediated ER export. PLD activity by itself does not lead to the recruitment of COPII to the membranes or ER export. However, PLD activity is required to support Sar1p-dependent membrane tubulation, the subsequent Sar1p-dependent recruitment of Sec23/24 and Sec13/31 COPII complexes to ER export sites and ER export. Sar1p recruitment to the membrane is PLD independent, yet activation of Sar1p is required to stimulate PLD activity on ER membranes, thus PLD is temporally regulated to support ER export. Regulated modification of membrane lipid composition is required to support the cooperative interactions that enable selective transport, as we demonstrate here for the mammalian COPII coat.
authors.affiliation: Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, 3500 Terrace Street, Pittsburgh, PA 15261, USA.
authors.forename: Purnima
authors.initials: P
authors.lastname: Pathre
authors.forename: Kuntala
authors.initials: K
authors.lastname: Shome
authors.forename: Anna
authors.initials: A
authors.lastname: Blumental-Perry
authors.forename: Anna
authors.initials: A
authors.lastname: Bielli
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Haney
authors.forename: Sean
authors.initials: S
authors.lastname: Alber
authors.forename: Simon C
authors.initials: SC
authors.lastname: Watkins
authors.forename: Guillermo
authors.initials: G
authors.lastname: Romero
authors.forename: Meir
authors.initials: M
authors.lastname: Aridor
mesh_terms: D020001:1-Butanol / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects*; D022181:COP-Coated Vesicles / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D005347:Fibroblasts / Q000201:enzymology / Q000378:metabolism* / Q000821:virology; D015971:Gene Expression Regulation, Enzymologic; D006160:Guanosine Triphosphate / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins; D010739:Phospholipase D / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D033921:Vesicular Transport Proteins; D014721:Vesicular stomatitis Indiana virus / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; D028861:Nuclear Pore Complex Proteins; D010750:Phosphoproteins; C079620:SEC13 protein, S cerevisiae; C106113:SEC31 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D006160:Guanosine Triphosphate; D020001:1-Butanol; D010739:Phospholipase D; D020559:Monomeric GTP-Binding Proteins; C077395:SAR1 protein, S cerevisiae