Immunophilin-like TWISTED DWARF1 modulates auxin efflux activities of Arabidopsis P-glycoproteins
Immunophilin-like TWISTED DWARF1 modulates auxin efflux activities of Arabidopsis P-glycoproteins
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DOI：
10.1074/jbc.m604604200
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发表时间：
2006-10-13
影响因子：
4.8
通讯作者：
Geisler, Markus
中科院分区：
文献类型：
--
作者：
Bouchard, Rodolphe;Bailly, Aurelien;Geisler, Markus
亲免素样蛋白TWISTED DWARF 1（TWD 1/FKBP 42）已被证明与多药耐药/P-糖蛋白（PGP）ATP结合盒转运蛋白PGP 1和PGP 19（MDR 1）物理相互作用。pgp 1/pgp 19和twd 1突变体植物的重叠表型表明，TWD 1在PGP介导的植物激素生长素的输出中具有积极的调节作用，生长素控制植物发育。在这里，我们提供的证据在细胞和植物水平，TWD 1控制PGP介导的生长素运输。twd 1和pgp 1/pgp 19细胞显示天然生长素吲哚-3-乙酸（IAA）的输出大大减少。组成型过度表达的PGP 1和PGP 19，而不是TWD 1，增强生长素输出。TWD 1和PGP 1在酵母和哺乳动物细胞中的共表达验证了调节作用的特异性。采用IAA-特异性微电极表明，IAA流入根伸长区的扰动和顶端转移在pgp 1/pgp 19和twd 1根。pgp 1/pgp 19和twd 1植物的成熟根显示游离IAA水平升高，这似乎占agravitropic根的行为。我们的数据表明一种新的模式PGP的监管通过FK 506结合蛋白样免疫亲，暗示可能的替代策略，以克服多药耐药。
The immunophilin-like protein TWISTED DWARF1 (TWD1/FKBP42) has been shown to physically interact with the multidrug resistance/P-glycoprotein (PGP) ATP-binding cassette transporters PGP1 and PGP19 (MDR1). Overlapping phenotypes of pgp1/pgp19 and twd1 mutant plants suggested a positive regulatory role of TWD1 in PGP-mediated export of the plant hormone auxin, which controls plant development. Here, we provide evidence at the cellular and plant levels that TWD1 controls PGP-mediated auxin transport. twd1 and pgp1/pgp19 cells showed greatly reduced export of the native auxin indole-3-acetic acid (IAA). Constitutive overexpression of PGP1 and PGP19, but not TWD1, enhanced auxin export. Coexpression of TWD1 and PGP1 in yeast and mammalian cells verified the specificity of the regulatory effect. Employing an IAA-specific microelectrode demonstrated that IAA influx in the root elongation zone was perturbed and apically shifted in pgp1/pgp19 and twd1 roots. Mature roots of pgp1/pgp19 and twd1 plants revealed elevated levels of free IAA, which seemed to account for agravitropic root behavior. Our data suggest a novel mode of PGP regulation via FK506-binding protein-like immunophilins, implicating possible alternative strategies to overcome multidrug resistance.