The juxtamembrane and carboxy-terminal domains of Arabidopsis PRK2 are critical for ROP-induced growth in pollen tubes.
The juxtamembrane and carboxy-terminal domains of Arabidopsis PRK2 are critical for ROP-induced growth in pollen tubes.
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DOI：
10.1093/jxb/ert323
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发表时间：
2013-12
影响因子：
6.9
通讯作者：
Zhang Y
中科院分区：
文献类型：
--
作者：
Zhao XY;Wang Q;Li S;Ge FR;Zhou LZ;McCormick S;Zhang Y
花粉管的极性生长是被子植物成功繁殖的关键步骤，由ROP GTP酶控制。ROP（Rho GTPases of plants）的时空激活需要一个复杂的调控系统，鸟嘌呤核苷酸交换因子（RopGEFs）是其中的关键成分。以前的研究表明，富含亮氨酸的重复序列受体样激酶，拟南芥花粉受体激酶2（AtPRK 2），与RopGEF 12的膜募集相互作用。然而，AtPRK 2介导的ROP体内激活的机制尚未确定。本文报道了AtPRK 2的过度表达诱导的管膨胀伴随着ROP-GTP的异位定位和肌动蛋白微丝的异位分布。一个潜在的激酶死亡突变体AtPRK 2K 366 R也诱导了管去极化，这表明AtPRK 2的过表达效应不需要其激酶活性。相比之下，AtPRK 2中的非催化结构域，即跨膜（JM）和羧基末端（CT）结构域的缺失，消除了其影响管极化的能力。值得注意的是，AtPRK 2K 366 R保留了与RopGEF 12相互作用的能力，而这些非催化结构域的AtPRK 2截短则没有。最后，已经表明AtPRK 2的JM和CT结构域不仅对其与RopGEF 12的相互作用至关重要，而且对其在质膜上的分布也至关重要。因此，这些结果为进一步了解花粉受体激酶介导的花粉管生长过程中的ROP激活提供了依据。
Polarized growth of pollen tubes is a critical step for successful reproduction in angiosperms and is controlled by ROP GTPases. Spatiotemporal activation of ROP (Rho GTPases of plants) necessitates a complex and sophisticated regulatory system, in which guanine nucleotide exchange factors (RopGEFs) are key components. It was previously shown that a leucine-rich repeat receptor-like kinase, Arabidopsis pollen receptor kinase 2 (AtPRK2), interacted with RopGEF12 for its membrane recruitment. However, the mechanisms underlying AtPRK2-mediated ROP activation in vivo are yet to be defined. It is reported here that over-expression of AtPRK2 induced tube bulging that was accompanied by the ectopic localization of ROP-GTP and the ectopic distribution of actin microfilaments. Tube depolarization was also induced by a potentially kinase-dead mutant, AtPRK2K366R, suggesting that the over-expression effect of AtPRK2 did not require its kinase activity. By contrast, deletions of non-catalytic domains in AtPRK2, i.e. the juxtamembrane (JM) and carboxy-terminal (CT) domains, abolished its ability to affect tube polarization. Notably, AtPRK2K366R retained the ability to interact with RopGEF12, whereas AtPRK2 truncations of these non-catalytic domains did not. Lastly, it has been shown that the JM and CT domains of AtPRK2 were not only critical for its interaction with RopGEF12 but also critical for its distribution at the plasma membrane. These results thus provide further insight into pollen receptor kinase-mediated ROP activation during pollen tube growth.
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影响因子：
7.8
作者：
Kost, B;Lemichez, E;Spielhofer, P;Hong, Y;Tolias, K;Carpenter, C;Chua, N H
通讯作者：
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影响因子：
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影响因子：
11.6
作者：
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通讯作者：
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DOI：
10.1073/pnas.1005366107
发表时间：
2010-10-12
影响因子：
11.1
作者：
Duan, Qiaohong;Kita, Daniel;Wu, Hen-Ming
通讯作者：
Wu, Hen-Ming
影响因子：
11.6
作者：
Gu, Y;Li, SD;Yang, ZB
通讯作者：
Yang, ZB