auxin; P-glycoprotein; ABCB; protein-protein interaction; FKBP; PPIase; auxin transport; immunophilins; calmodulin
Wang Bangjun, Bailly Aurélien, Zwiewka Marta, Henrichs Sina, Azzarello Elisa, Mancuso Stefano, Maeshima Masayoshi, Friml Jirí, Schulz Alexander, Geisler Markus (2013), Arabidopsis TWISTED DWARF1 Functionally Interacts with Auxin Exporter ABCB1 on the Root Plasma Membrane., in
The Plant cell, in press(in press), 1-13.
Barbez Elke, Kubeš Martin, Rolčík Jakub, Béziat Chloé, Pěnčík Aleš, Wang Bangjun, Rosquete Michel Ruiz, Zhu Jinsheng, Dobrev Petre I, Lee Yuree, Zažímalovà Eva, Petrášek Jan, Geisler Markus, Friml Jiří, Kleine-Vehn Jürgen (2012), A novel putative auxin carrier family regulates intracellular auxin homeostasis in plants., in
Nature comm., 485(7396), 119-22.
Kamimoto Yoshihisa, Terasaka Kazuyoshi, Hamamoto Masafumi, Takanashi Kojiro, Fukuda Shoju, Shitan Nobukazu, Sugiyama Akifumi, Suzuki Hideyuki, Shibata Daisuke, Wang Bangjun, Pollmann Stephan, Geisler Markus, Yazaki Kazufumi (2012), Arabidopsis ABCB21 is a facultative auxin importer/exporter regulated by cytoplasmic auxin concentration., in
Plant & cell physiology, 53(12), 2090-100.
Ding Zhaojun, Wang Bangjun, Moreno Ignacio, Dupláková Nikoleta, Simon Sibu, Carraro Nicola, Reemmer Jesica, Pěnčík Aleš, Chen Xu, Tejos Ricardo, Skůpa Petr, Pollmann Stephan, Mravec Jozef, Petrášek Jan, Zažímalová Eva, Honys David, Rolčík Jakub, Murphy Angus, Orellana Ariel, Geisler Markus, Friml Jiří (2012), ER-localized auxin transporter PIN8 regulates auxin homeostasis and male gametophyte development in Arabidopsis., in
Nature communications, 3, 941-941.
Burgardt Noelia Inés, Linnert Miriam, Weiwad Matthias, Geisler Markus, Lücke Christian (2012), NMR assignments of the FKBP-type PPIase domain of FKBP42 from Arabidopsis thaliana., in
Biomolecular NMR assignments, 6(2), 185-8.
Henrichs Sina, Wang Bangjun, Fukao Yoichiro, Zhu Jinsheng, Charrier Laurence, Bailly Aurélien, Oehring Sophie C, Linnert Miriam, Weiwad Matthias, Endler Anne, Nanni Paolo, Pollmann Stephan, Mancuso Stefano, Schulz Alexander, Geisler Markus (2012), Regulation of ABCB1/PGP1-catalysed auxin transport by linker phosphorylation., in
The EMBO journal, 31(13), 2965-80.
Wang Bangjun, Henrichs Sina, Geisler Markus (2012), The AGC kinase, PINOID, blocks interactive ABCB/PIN auxin transport., in
Plant signaling & behavior, 7(12), 1515-1518.
Kuhn Benjamin M, Geisler Markus, Bigler Laurent, Ringli Christoph (2011), Flavonols accumulate asymmetrically and affect auxin transport in Arabidopsis., in
Plant physiology, 156(2), 585-95.
Bailly Aurélien, Yang Haibing, Martinoia Enrico, Geisler Markus, Murphy Angus S (2011), Plant Lessons: Exploring ABCB Functionality Through Structural Modeling., in
Frontiers in plant science, 2, 108-108.
Song Won-Yong, Choi Kwan Sam, Kim Do Young, Geisler Markus, Park Jiyoung, Vincenzetti Vincent, Schellenberg Maja, Kim Sun Ha, Lim Yong Pyo, Noh Eun Woon, Lee Youngsook, Martinoia Enrico (2010), Arabidopsis PCR2 is a zinc exporter involved in both zinc extrusion and long-distance zinc transport., in
The Plant cell, 22(7), 2237-52.
Ruzicka Kamil, Strader Lucia C, Bailly Aurélien, Yang Haibing, Blakeslee Joshua, Langowski Lukasz, Nejedlá Eliska, Fujita Hironori, Itoh Hironori, Syono Kunihiko, Hejátko Jan, Gray William M, Martinoia Enrico, Geisler Markus, Bartel Bonnie, Murphy Angus S, Friml Jirí (2010), Arabidopsis PIS1 encodes the ABCG37 transporter of auxinic compounds including the auxin precursor indole-3-butyric acid., in
Proceedings of the National Academy of Sciences of the United States of America, 107(23), 10749-53.
Song Won-Yong, Park Jiyoung, Mendoza-Cózatl David G, Suter-Grotemeyer Marianne, Shim Donghwan, Hörtensteiner Stefan, Geisler Markus, Weder Barbara, Rea Philip A, Rentsch Doris, Schroeder Julian I, Lee Youngsook, Martinoia Enrico (2010), Arsenic tolerance in Arabidopsis is mediated by two ABCC-type phytochelatin transporters., in
Proceedings of the National Academy of Sciences of the United States of America, 107(49), 21187-92.
Kim Jun-Young, Henrichs Sina, Bailly Aurélien, Vincenzetti Vincent, Sovero Valpuri, Mancuso Stefano, Pollmann Stephan, Kim Daehwang, Geisler Markus, Nam Hong-Gil (2010), Identification of an ABCB/P-glycoprotein-specific inhibitor of auxin transport by chemical genomics., in
The Journal of biological chemistry, 285(30), 23309-17.
de Carbonnel Matthieu, Davis Phillip, Roelfsema M Rob G, Inoue Shin-Ichiro, Schepens Isabelle, Lariguet Patricia, Geisler Markus, Shimazaki Ken-Ichiro, Hangarter Roger, Fankhauser Christian (2010), The Arabidopsis PHYTOCHROME KINASE SUBSTRATE2 protein is a phototropin signaling element that regulates leaf flattening and leaf positioning., in
Plant physiology, 152(3), 1391-405.
Local gradients of the signaling molecule auxin (IAA) are the primary determinants for many aspects of plant physiology and development. In agreement with the chemiosmotic theory, auxin efflux catalyzed by members of PIN-FORMED (PIN) and ABCB/P-GLYCOPROTEIN (PGP) families is the rate-limiting step and requires therefore strict regulation.ABCB-mediated export has been shown to be modulated by PINs and the FKBP (FK506-binding protein)-like TWISTED DWARF1 (TWD1)/FKBP42 by means of protein-protein interaction. TWD1 positively regulates the activity of ABCB1/PGP1 and close ABCB19/PGP19/MDR1 which is documented by a close overlap between twd1 and abcb1 abcb19 phenotypes. Interestingly, TWD1-ABCB1 interaction is disrupted by auxin transport inhibitors, like NPA or flavonols, and enhanced by IAA itself, resulting in blocked or stimulated auxin transport in planta, respectively. As a consequence, twd1 plants are NPA-insensitive suggesting that TWD1 functions as a flux sensor of ABCB-mediated auxin transport.However, in contrast to its physiological relevance, the underlying mechanisms are entirely unclear. The N-terminal PPIase domain, functioning as cis-trans peptidylprolyl isomerase in canonical FKBPs, binds the C-terminal nucleotide binding fold (NBD2) of ABCBs. Initially it was therefore thought that TWD1 interaction would block IAA or ATP access. In light of recent findings and the unequal ABCB1/TWD1 stoichiometry a transient mode of action was predicted. In this project we intend to precisely map TWD1-ABCB interfaces and to elucidate the mechanism of ABCB activation by TWD1 docking.Previous unsuccessful mapping trials suggest that the TWD1-ABCB1 interaction employs 3D binding surfaces in both molecules. Therefore, we aim to precisely determine essential surface residues by use of combinations of bioinformatical (in silico docking), biochemical (ABCB1 peptide scans) and structural tools (co-crystallization of purified ABCB1-NBD2 and TWD1 proteins). Moreover we aim to demonstrate intramolecular, conformational changes in the NBD2 of ABCBs that are proposed to be catalyzed by a TWD1 intrinsic chaperone or a hidden PPIase activity, that would account for altered substrate affinities and specificities. In agreement, a stabilizing, chaperone activity of TWD1 was detected in vitro but all attempts to detect a PPIase activity for TWD1 have been unsuccessful. This is in analogy to closely related human FKBP38, that was recently shown to own a PPIase activity upon Ca2+/calmodulin-binding, forming the basis for target protein binding. Ca2+/calmodulin binding, established also for TWD1, leads apparently to a conformational change in the docking PPIase domain that is only able to bind FK506 upon activation.In a first step we will prove a hidden PPIase activity of the TWD1 FKBD that is activated by Ca2+/calmodulin. Consequently, we aim to show that activation stabilizes NBD2-TWD1 complex formation. Second, in order to demonstrate intramolecular NBD2 shifts, caused by TWD1 docking, as the primary cause of altered ABCB activity, we will employ NMR spectroscopy, quenching of intrinsic tryptophane fluorescence and NEM labeling of single-cysteine NBD2. Mechanistic implications from the structure analysis will be verified by site-directed mutagenesis of key residues analyzed in vitro and in yeast using BRET and auxin transport assays. Finally this novel mechanism will be validated by functional complementation of abcb mutants with mutated, genomic ABCB-NBD2 constructs, followed by a detailed physiological analysis.The outcome should provide a deep insight into the regulation of auxin transport via plant ABCBs and the establishment of local auxin gradients controlling virtually all steps of plant development. Transfer of this knowledge might later on open new strategies for the directed genetic or chemical manipulation of plant size or stem diameter, being critical for agricultural productivity. Finally, this novel mechanism controlling ABCB activity and substrate specificity by immunophilins might as well be of clinical relevance, as multidrug resistance attributed mainly to ABCBs are the major cause for chemotherapy failure.