Irshad Muhammad, Canut Hervé, Borderies Gisèle, Pont-Lezica Rafael, Jamet Elisabeth
Surfaces cellulaires et Signalisation chez les Végétaux, UMR 5546 CNRS - UPS-Université de Toulouse, Pôle de Biotechnologie Végétale, 24 chemin de Borde-Rouge, BP 42617 Auzeville, 31326 Castanet-Tolosan, France.
BMC Plant Biol. 2008 Sep 16;8:94. doi: 10.1186/1471-2229-8-94.
Cell elongation in plants requires addition and re-arrangements of cell wall components. Even if some protein families have been shown to play roles in these events, a global picture of proteins present in cell walls of elongating cells is still missing. A proteomic study was performed on etiolated hypocotyls of Arabidopsis used as model of cells undergoing elongation followed by growth arrest within a short time.
Two developmental stages (active growth and after growth arrest) were compared. A new strategy consisting of high performance cation exchange chromatography and mono-dimensional electrophoresis was established for separation of cell wall proteins. This work allowed identification of 137 predicted secreted proteins, among which 51 had not been identified previously. Apart from expected proteins known to be involved in cell wall extension such as xyloglucan endotransglucosylase-hydrolases, expansins, polygalacturonases, pectin methylesterases and peroxidases, new proteins were identified such as proteases, proteins related to lipid metabolism and proteins of unknown function.
This work highlights the CWP dynamics that takes place between the two developmental stages. The presence of proteins known to be related to cell wall extension after growth arrest showed that these proteins may play other roles in cell walls. Finally, putative regulatory mechanisms of protein biological activity are discussed from this global view of cell wall proteins.
植物细胞伸长需要细胞壁成分的添加和重新排列。尽管一些蛋白质家族已被证明在这些过程中发挥作用，但伸长细胞细胞壁中蛋白质的整体情况仍不清楚。本研究以拟南芥黄化苗下胚轴为模型，研究细胞在短时间内经历伸长然后生长停滞过程中的蛋白质组学变化。
比较了两个发育阶段（活跃生长阶段和生长停滞阶段）。建立了一种由高效阳离子交换色谱和一维电泳组成的新策略，用于分离细胞壁蛋白。这项工作鉴定出137种预测的分泌蛋白，其中51种以前未被鉴定过。除了已知参与细胞壁伸展的预期蛋白质，如木葡聚糖内转糖基酶-水解酶、扩展蛋白、多聚半乳糖醛酸酶、果胶甲酯酶和过氧化物酶外，还鉴定出了新的蛋白质，如蛋白酶、与脂质代谢相关的蛋白质和功能未知的蛋白质。
这项工作突出了两个发育阶段之间发生的细胞壁蛋白动态变化。生长停滞后已知与细胞壁伸展相关的蛋白质的存在表明，这些蛋白质可能在细胞壁中发挥其他作用。最后，从细胞壁蛋白的整体视角讨论了蛋白质生物活性的假定调控机制。
