Auxin efflux by PIN-FORMED proteins is activated by two different protein kinases, D6 PROTEIN KINASE and PINOID

• Published in: eLife Vol. 3; pp. 1 - 25
• Main Authors: Zourelidou, Melina, Absmanner, Birgit, Weller, Benjamin, Barbosa, Inês C R, Willige, Björn C, Fastner, Astrid, Streit, Verena, Port, Sarah A, Colcombet, Jean, de la Fuente van Bentem, Sergio, Hirt, Heribert, Kuster, Bernhard, Schulze, Waltraud X, Hammes, Ulrich Z, Schwechheimer, Claus
• Format: Journal Article
• Language: English
• Published: England eLife Sciences Publications Ltd 19.06.2014; eLife Sciences Publication; eLife Sciences Publications, Ltd
• Subjects: AGC kinase; Animals; Arabidopsis - metabolism; Arabidopsis Proteins - metabolism; auxin; auxin transport; Biological Transport; Biology; Cell Membrane - metabolism; Indoleacetic Acids - chemistry; Kinases; Life Sciences; Microscopy, Confocal; Mutation; Oocytes - cytology; Oocytes - metabolism; Peptides; Phosphorylation; Plant Biology; Plants; Protein kinase; Protein Kinases - metabolism; Protein-Serine-Threonine Kinases - metabolism; Proteins; Vegetal Biology; Xenopus; plant biology; auxin; AGC kinases; auxin transport; arabidopsis; protein kinase
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/elife.02860

The development and morphology of vascular plants is critically determined by synthesis and proper distribution of the phytohormone auxin. The directed cell-to-cell distribution of auxin is achieved through a system of auxin influx and efflux transporters. PIN-FORMED (PIN) proteins are proposed auxin efflux transporters, and auxin fluxes can seemingly be predicted based on the--in many cells--asymmetric plasma membrane distribution of PINs. Here, we show in a heterologous Xenopus oocyte system as well as in Arabidopsis thaliana inflorescence stems that PIN-mediated auxin transport is directly activated by D6 PROTEIN KINASE (D6PK) and PINOID (PID)/WAG kinases of the Arabidopsis AGCVIII kinase family. At the same time, we reveal that D6PKs and PID have differential phosphosite preferences. Our study suggests that PIN activation by protein kinases is a crucial component of auxin transport control that must be taken into account to understand auxin distribution within the plant.