MAPKs entry into the nucleus at specific interchromatin domains in plant differentiation and proliferation processes
MAPKs entry into the nucleus at specific interchromatin domains in plant differentiation and proliferation processes
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DOI：
10.1016/s1047-8477(02)00542-7
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发表时间：
2002-10-01
影响因子：
3
通讯作者：
Risueño, MC
中科院分区：
文献类型：
--
作者：
Coronado, MJ;González-Melendi, P;Risueño, MC
丝裂原活化蛋白激酶（MAPK）参与真核生物（包括植物）细胞外刺激的信号传导。不同的MAPKs最近已被证明在植物细胞增殖和发育过程中表达，如花粉发育和胚胎发生，但这些MAPKs在细胞核中靶向的结构亚域尚未被表征。我们已经确定了ERK同源物的表达和亚细胞定位的变化，属于MAPK家族的蛋白质，和MAPK活性形式在两个植物发育过程中，涉及分化（花粉成熟）和增殖（花粉胚胎发生的起始）。免疫荧光和免疫金标记的研究表明，在物种的分化和增殖的进展是伴随着增加的ERK和MAPK的活化的表达一起易位到细胞核。结合超微结构细胞化学和免疫金的RNA和磷酸化蛋白，我们已经确定了核网站住房这些MAPK的区域内的染色质间区域丰富的RNA和磷蛋白，包括集群的染色质间颗粒。这可能表明这些MAPK通过磷酸化在转录和加工机制激活的早期事件中的作用，随后将被募集到转录位点。MAPKs的核定位与两种植物发育过程中细胞周期的进展和分化的承诺之间存在相关性。(C)2002 Elsevier Science（美国）。All rights reserved.
Mitogen-activated protein kinases (MAPKs) are involved in the signaling of extracellular stimuli in eukaryotes, including plants. Different MAPKs have recently been shown to be expressed during plant cell proliferation and developmental processes such as pollen development and embryogenesis, but the structural subdomain where these MAPKs are targeted in the nucleus has not yet been characterized. We have determined the changes in the expression and subcellular localization of ERK homologues, proteins belonging to the MAPK family, and MAPK-active forms in two plant developmental processes which involved differentiation (pollen maturation) and proliferation (the initials of pollen embryogenesis). Immunofluorescence and immunogold labeling in the species studied showed that the progression of differentiation and proliferation was accompanied by an increase in the expression of ERKs and MAPK activation together with a translocation to the nucleus. Combining ultrastructural cytochemistry and immunogold for RNA and phosphorylated proteins we have identified the nuclear sites housing these MAPKs in areas of the interchromatin region enriched in RNA and phosphoproteins that include clusters of interchromatin granules. This could suggest a role of these MAPKs in the early events of activation of the transcription and processing machinery, via phosphorylation, which subsequently would be recruited to the transcription sites. The association of the nuclear localization of MAPKs with the progression through the cell cycle and the commitment toward differentiation in the two plant developmental processes can be correlated. (C) 2002 Elsevier Science (USA). All rights reserved.