The M3 phosphorylation motif has been functionally conserved for intracellular trafficking of long-looped PIN-FORMEDs in the Arabidopsis root hair cell.
The M3 phosphorylation motif has been functionally conserved for intracellular trafficking of long-looped PIN-FORMEDs in the Arabidopsis root hair cell.
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M3磷酸化基序在拟南芥根部毛细胞中的细胞内运输在功能上保守了。
DOI：
10.1186/1471-2229-13-189
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发表时间：
2013-11-26
影响因子：
5.3
通讯作者：
Cho HT
中科院分区：
文献类型：
--
作者：
Sasayama D;Ganguly A;Park M;Cho HT
PIN 形 (PIN) 外排载体通过在质膜 (PM) 中表现出动态和多样化的不对称定位模式，有助于极性生长素运输和植物发育。 PIN 中央亲水环 (HL) 的磷酸化与 PIN 运输的调节有关。最近，我们报道了 PIN3-HL 中的可磷酸化基序 (M3) 对于 PIN3 的极性、细胞内运输和生物学功能是必需的。在这项研究中，我们使用根毛系统进行 PIN 活性测定，研究了该基序在长 HL PIN 中是否在功能上保守。野生型 PIN1、2 或 7 的根毛特异性过表达通过消耗根毛细胞中的生长素水平而极大地抑制根毛生长，而 M3 磷酸化缺陷型 PIN 突变体的过表达未能抑制根毛生长。与这种根毛表型一致，M3 磷酸化缺陷的 PIN1 和 PIN7 的 PM 定位被部分破坏，导致生长素外流减少并恢复根毛生长。这些磷酸化突变 PIN 系中布雷菲德菌素 A 区室的部分形成也表明它们的 PM 靶向部分被破坏。另一方面，与PIN1和PIN7突变蛋白相比，M3磷酸化缺陷的PIN2蛋白几乎检测不到。然而，通过渥曼青霉素处理，突变型 PIN2 蛋白水平几乎恢复至野生型 PIN2 水平，表明 PIN2 的 M3 基序与其他 PIN 不同，涉及 PIN2 向液泡裂解途径的运输。这些结果表明，M3 磷酸化基序在功能上是保守的，可调节长 HL PIN 的细胞内运输，但其运输中的具体功能在 PIN 成员之间存在差异。
PIN-FORMED (PIN) efflux carriers contribute to polar auxin transport and plant development by exhibiting dynamic and diverse asymmetrical localization patterns in the plasma membrane (PM). Phosphorylation of the central hydrophilic loop (HL) of PINs has been implicated in the regulation of PIN trafficking. Recently, we reported that a phosphorylatable motif (M3) in the PIN3-HL is necessary for the polarity, intracellular trafficking, and biological functions of PIN3. In this study, using the root hair system for PIN activity assay, we investigated whether this motif has been functionally conserved among long-HL PINs. Root hair-specific overexpression of wild-type PIN1, 2, or 7 greatly inhibited root hair growth by depleting auxin levels in the root hair cell, whereas overexpression of M3 phosphorylation-defective PIN mutants failed to inhibit root hair growth. Consistent with this root hair phenotype, the PM localization of M3 phosphorylation-defective PIN1 and PIN7 was partially disrupted, resulting in less auxin efflux and restoration of root hair growth. Partial formation of brefeldin A-compartments in these phosphorylation-mutant PIN lines also suggested that their PM targeting was partially disrupted. On the other hand, compared with the PIN1 and PIN7 mutant proteins, M3-phosphorylation-defective PIN2 proteins were almost undetectable. However, the mutant PIN2 protein levels were restored by wortmannin treatment almost to the wild-type PIN2 level, indicating that the M3 motif of PIN2, unlike that of other PINs, is implicated in PIN2 trafficking to the vacuolar lytic pathway. These results suggest that the M3 phosphorylation motif has been functionally conserved to modulate the intracellular trafficking of long-HL PINs, but its specific function in trafficking has diverged among PIN members.
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影响因子：
64.5
作者：
Geldner, N;Anders, N;Jürgens, G
通讯作者：
Jürgens, G
影响因子：
64.8
作者：
Blilou, I;Xu, J;Scheres, B
通讯作者：
Scheres, B
DOI：
10.1073/pnas.0808073105
发表时间：
2008-11-18
影响因子：
11.1
作者：
Kleine-Vehn, Juergen;Leitner, Johannes;Friml, Jiri
通讯作者：
Friml, Jiri
影响因子：
21.3
作者：
Ding, Zhaojun;Galvan-Ampudia, Carlos S.;Friml, Jiri
通讯作者：
Friml, Jiri
影响因子：
64.8
作者：
Jaillais, Yvon;Fobis-Loisy, Isabelle;Gaude, Thierry
通讯作者：
Gaude, Thierry