Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis.
Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis.
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肌动蛋白微丝变化对植物细胞力学中细胞板发育的贡献的定量分析。
DOI：
10.1186/1471-2229-8-80
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发表时间：
2008-07-17
影响因子：
5.3
通讯作者：
Hasezawa, Seiichiro
中科院分区：
文献类型：
--
作者：
Higaki, Takumi;Kutsuna, Natsumaro;Sano, Toshio;Hasezawa, Seiichiro
植物细胞通过从每个分裂细胞的中心到外围形成新的横壁（称为细胞板）进行分裂。细胞板的形成发生在成膜体中，成膜体是一种由膜、微管 (MT) 和肌动蛋白微丝 (MF) 组成的复杂结构。先前发现成膜体 MT 的破坏可以完全抑制细胞板的形成和扩张，表明它们在细胞板膜和材料的运输中发挥着至关重要的作用。相反，破坏 MF 仅延迟细胞板扩张，但不能完全抑制细胞板形成。尽管有这些发现，MT 和 MF 的重要性和分子机制仍然很大程度上未知。通过稳定表达 GFP-肌动蛋白结合域 2 (GFP-ABD2) 融合蛋白的烟草 BY-2 细胞的实时成像来监测 MF 分布的时间序列变化，该融合蛋白与标记细胞板的内吞示踪剂 FM4-64 进行有效共染色。在胞质分裂过程中，MF 在新分离的子核附近向新兴细胞板聚集，随后接近扩展的细胞板边缘。用肌动蛋白聚合抑制剂处理导致细胞板扩张率下降，通过延时成像和回归分析对其进行量化。我们的结果证明了 MF 对细胞板扩张的贡献随时间的变化； MF 破坏导致细胞板扩张率在胞质分裂早期下降约 10%，但在晚期下降约 25%。 MF 破坏还会导致早期细胞板畸形，表明 MF 参与早期细胞板形成和扩张。肌动蛋白聚合抑制剂和肌球蛋白 ATP 酶抑制剂分别处理也抑制了细胞板周围内体的动态运动。此外，内质网（ER）的延时成像显示，MF 参与了后期成膜体中 ER 的积累。通过 GFP-ABD2 的表达和 FM4-64 的活体染色，可以在活细胞的整个植物胞质分裂过程中跟踪 MF 和细胞板的动态。药物治疗和实时成像分析还使我们能够量化胞质分裂过程中 MF 对细胞板扩张的贡献。我们的结果表明，MF 通过调节内膜动力学在细胞板形成和扩张中发挥重要作用。
Plant cells divide by the formation of new cross walls, known as cell plates, from the center to periphery of each dividing cell. Formation of the cell plate occurs in the phragmoplast, a complex structure composed of membranes, microtubules (MTs) and actin microfilaments (MFs). Disruption of phragmoplast MTs was previously found to completely inhibit cell plate formation and expansion, indicative of their crucial role in the transport of cell plate membranes and materials. In contrast, disruption of MFs only delays cell plate expansion but does not completely inhibit cell plate formation. Despite such findings, the significance and molecular mechanisms of MTs and MFs remain largely unknown. Time-sequential changes in MF-distribution were monitored by live imaging of tobacco BY-2 cells stably expressing the GFP-actin binding domain 2 (GFP-ABD2) fusion protein, which vitally co-stained with the endocytic tracer, FM4-64, that labels the cell plate. During cytokinesis, MFs accumulated near the newly-separated daughter nuclei towards the emerging cell plate, and subsequently approached the expanding cell plate edges. Treatment with an actin polymerization inhibitor caused a decrease in the cell plate expansion rate, which was quantified using time-lapse imaging and regression analysis. Our results demonstrated time-sequential changes in the contribution of MFs to cell plate expansion; MF-disruption caused about a 10% decrease in the cell plate expansion rate at the early phase of cytokinesis, but about 25% at the late phase. MF-disruption also caused malformation of the emerging cell plate at the early phase, indicative of MF involvement in early cell plate formation and expansion. The dynamic movement of endosomes around the cell plate was also inhibited by treatment with an actin polymerization inhibitor and a myosin ATPase inhibitor, respectively. Furthermore, time-lapse imaging of the endoplasmic reticulum (ER) revealed that MFs were involved in ER accumulation in the phragmoplast at the late phase. By expression of GFP-ABD2 and vital staining with FM4-64, the dynamics of MFs and the cell plate could be followed throughout plant cytokinesis in living cells. Pharmacological treatment and live imaging analysis also allowed us to quantify MF contribution to cell plate expansion during cytokinesis. Our results suggest that MFs play significant roles in cell plate formation and expansion via regulation of endomembrane dynamics.
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影响因子：
4
作者：
Austin, JR;Seguí-Simarro, JM;Staehelin, LA
通讯作者：
Staehelin, LA
影响因子：
2
作者：
Bolte, S;Talbot, C;Satiat-Jeunemaitre, B
通讯作者：
Satiat-Jeunemaitre, B
影响因子：
4
作者：
Dhonukshe, Pankaj;Samaj, Jozef;Friml, Jiri
通讯作者：
Friml, Jiri
影响因子：
7.4
作者：
Baluska, F;Hlavacka, A;Volkmann, D
通讯作者：
Volkmann, D
影响因子：
4.9
作者：
Hayashi, Tomomi;Sano, Toshio;Hasezawa, Seiichiro
通讯作者：
Hasezawa, Seiichiro