title: Expression and characterization of a barley phosphatidylinositol transfer protein structurally homologous to the yeast Sec14p protein.
abstract: Phosphatidylinositol transfer proteins (PITPs) include a large group of proteins implicated in the non-vesicular traffic of phosphatidylinositol (PI) between membranes. In yeast, the structure and function of the PITP Sec14-p protein have been well characterized. In contrast, the knowledge on plant PITP proteins is very scarce. In this work, we characterized a novel type of PITP protein in barley named HvSec14p and related to the yeast Sec14-p protein. Our data reveal that HvSec14p consists of only the Sec14p-domain structurally homologous to the yeast phosphoinositide binding domain. We show that HvSec14p expression is up-regulated at both transcript and protein levels at specific stages of development during seed formation and germination, and in leaves of a drought-tolerant barley genotype under osmotic constraints. Modeling analyses of the protein three-dimensional structure revealed its capacity to dock the phosphoinositides, PtdIns(3)P, PtdIns(4)P, PtdIns(5)P and PtdIns(3,5)P2. Consistently, the recombinant HvSec14p protein is able to bind in vitro most PIP types, the highest affinity being observed with PtdIns(3,5)P2. Based on the high gene expression at specific developmental stages and in drought-tolerant barley genotypes, we propose that HvSec14p plays essential roles in the biogenesis of membranes in expanding cells and in their preservation under osmotic stress conditions.
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland. Electronic address: akie@igr.poznan.pl.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kiełbowicz-Matuk
authors.affiliation: Molecular Biophysics Department, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland. Electronic address: ewas@amu.edu.pl.
authors.forename: Ewa
authors.initials: E
authors.lastname: Banachowicz
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland. Electronic address: atur@igr.poznan.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Turska-Tarska
authors.affiliation: CEA, DSV, IBEB, Laboratoire d'Ecophysiologie Moléculaire des Plantes, Saint-Paul-lez-Durance, F-13108, France; CNRS, UMR 7265 Biologie Végétale & Microbiologie Environnementale, Saint-Paul-lez-Durance, F-13108, France; Aix-Marseille Université, Saint-Paul-lez-Durance, F-13108, France. Electronic address: pascal.rey@cea.fr.
authors.forename: Pascal
authors.initials: P
authors.lastname: Rey
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland. Electronic address: tror@igr.poznan.pl.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Rorat
mesh_terms: D000595:Amino Acid Sequence; D055864:Droughts; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D018525:Germination / Q000187:drug effects / Q000235:genetics; D001467:Hordeum / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D008958:Models, Molecular; D010716:Phosphatidylinositols / Q000378:metabolism; D049294:Phospholipid Transfer Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology; D040681:Structural Homology, Protein; D013329:Structure-Activity Relationship
chemical_list: D010716:Phosphatidylinositols; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids; D010940:Plant Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C483438:SEC14 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D012965:Sodium Chloride
keywords: Barley; Drought; Osmotic stress; Phosphatidylinositol transfer protein (PITP); Salinity; Sec14p