title: Identification and functional characterization of the Arabidopsis Snf1-related protein kinase SnRK2.4 phosphatidic acid-binding domain.
abstract: Phosphatidic acid (PA) is an important signalling lipid involved in various stress-induced signalling cascades. Two SnRK2 protein kinases (SnRK2.4 and SnRK2.10), previously identified as PA-binding proteins, are shown here to prefer binding to PA over other anionic phospholipids and to associate with cellular membranes in response to salt stress in Arabidopsis roots. A 42 amino acid sequence was identified as the primary PA-binding domain (PABD) of SnRK2.4. Unlike the full-length SnRK2.4, neither the PABD-YFP fusion protein nor the SnRK2.10 re-localized into punctate structures upon salt stress treatment, showing that additional domains of the SnRK2.4 protein are required for its re-localization during salt stress. Within the PABD, five basic amino acids, conserved in class 1 SnRK2s, were found to be necessary for PA binding. Remarkably, plants overexpressing the PABD, but not a non-PA-binding mutant version, showed a severe reduction in root growth. Together, this study biochemically characterizes the PA-SnRK2.4 interaction and shows that functionality of the SnRK2.4 PABD affects root development.
authors: Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands.
authors: Magdalena M
authors: MM
authors: Julkowska
authors: Fionn
authors: F
authors: McLoughlin
authors: Carlos S
authors: CS
authors: Galvan-Ampudia
authors: Johanna M
authors: JM
authors: Rankenberg
authors: Dorota
authors: D
authors: Kawa
authors: Maria
authors: M
authors: Klimecka
authors: Michel A
authors: MA
authors: Haring
authors: Teun
authors: T
authors: Munnik
authors: Edgar E
authors: EE
authors: Kooijman
authors: Christa
authors: C
authors: Testerink
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010712:Phosphatidic Acids / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D010766:Phosphorylation; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D010712:Phosphatidic Acids; D010743:Phospholipids; D011993:Recombinant Fusion Proteins; C492978:SnRK2 protein, Arabidopsis; D012965:Sodium Chloride; D017346:Protein Serine-Threonine Kinases
keywords: SnRK2.10; phosphatidic acid; phospholipid binding; root system architecture