title: Identification of novel candidate phosphatidic acid-binding proteins involved in the salt-stress response of Arabidopsis thaliana roots.
abstract: PA (phosphatidic acid) is a lipid second messenger involved in an array of processes occurring during a plant's life cycle. These include development, metabolism, and both biotic and abiotic stress responses. PA levels increase in response to salt, but little is known about its function in the earliest responses to salt stress. In the present study we have combined an approach to isolate peripheral membrane proteins of Arabidopsis thaliana roots with lipid-affinity purification, to identify putative proteins that interact with PA and are recruited to the membrane in response to salt stress. Of the 42 putative PA-binding proteins identified by MS, a set of eight new candidate PA-binding proteins accumulated at the membrane fraction after 7 min of salt stress. Among these were CHC (clathrin heavy chain) isoforms, ANTH (AP180 N-terminal homology) domain clathrin-assembly proteins, a putative regulator of potassium transport, two ribosomal proteins, GAPDH (glyceraldehyde 3-phosphate dehydrogenase) and a PI (phosphatidylinositol) 4-kinase. PA binding and salt-induced membrane recruitment of GAPDH and CHC were confirmed by Western blot analysis of the cellular fractions. In conclusion, the approach of the present study is an effective way to isolate biologically relevant lipid-binding proteins and provides new leads in the study of PA-mediated salt-stress responses in roots.
authors: University of Amsterdam, Swammerdam Institute for Life Sciences, Section Plant Physiology, Postbus 94215, 1090 GE Amsterdam, The Netherlands.
authors: Fionn
authors: F
authors: McLoughlin
authors: Steven A
authors: SA
authors: Arisz
authors: Henk L
authors: HL
authors: Dekker
authors: Gertjan
authors: G
authors: Kramer
authors: Chris G
authors: CG
authors: de Koster
authors: Michel A
authors: MA
authors: Haring
authors: Teun
authors: T
authors: Munnik
authors: Christa
authors: C
authors: Testerink
mesh_terms: D000465:Algorithms; D017360:Arabidopsis / Q000737:chemistry* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000302:isolation & purification* / Q000378:metabolism* / Q000502:physiology; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism; D008954:Models, Biological; D010712:Phosphatidic Acids / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D020543:Proteome / Q000032:analysis / Q000187:drug effects / Q000302:isolation & purification; D055049:Salt Tolerance / Q000235:genetics; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D008565:Membrane Proteins; D010712:Phosphatidic Acids; D020543:Proteome; D012965:Sodium Chloride