Phospholipid composition and a polybasic motif determine D6 PROTEIN KINASE polar association with the plasma membrane and tropic responses.
Polar transport of the phytohormone auxin through PIN-FORMED (PIN) auxin efflux carriers is essential for the spatiotemporal control of plant development. The Arabidopsis thaliana serine/threonine kinase D6 PROTEIN KINASE (D6PK) is polarly localized at the plasma membrane of many cells where it colocalizes with PINs and activates PIN-mediated auxin efflux. Here, we show that the association of D6PK with the basal plasma membrane and PINs is dependent on the phospholipid composition of the plasma membrane as well as on the phosphatidylinositol phosphate 5-kinases PIP5K1 and PIP5K2 in epidermis cells of the primary root. We further show that D6PK directly binds polyacidic phospholipids through a polybasic lysine-rich motif in the middle domain of the kinase. The lysine-rich motif is required for proper PIN3 phosphorylation and for auxin transport-dependent tropic growth. Polybasic motifs are also present at a conserved position in other D6PK-related kinases and required for membrane and phospholipid binding. Thus, phospholipid-dependent recruitment to membranes through polybasic motifs might not only be required for D6PK-mediated auxin transport but also other processes regulated by these, as yet, functionally uncharacterized kinases.
Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, Freising 85354, Germany.
Inês C R
IC
Barbosa
Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, Freising 85354, Germany.
Hiromasa
H
Shikata
Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, Freising 85354, Germany.
Melina
M
Zourelidou
Institute for Biochemistry and Biotechnology, Cellular Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3, Halle 06120, Germany.
Mareike
0000-0002-2324-1849
M
Heilmann
Institute for Biochemistry and Biotechnology, Cellular Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3, Halle 06120, Germany.
Ingo
I
Heilmann
Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, Freising 85354, Germany claus.schwechheimer@wzw.tum.de.
Claus
0000-0003-0269-2330
C
Schwechheimer
D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D010716:Phosphatidylinositols / Q000737:chemistry*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000378:metabolism*
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C449300:PIN3 protein, Arabidopsis; D010716:Phosphatidylinositols; D010937:Plant Growth Regulators; C585918:D6PK protein, Arabidopsis; D011494:Protein Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase
Auxin transport; D6PK; Lysine-rich motif; Phospholipid; Plasma membrane