Max Planck Institute of Molecular Plant Physiology Golm, Germany ; Max-Delbrück-Centrum für Molekulare Medizin Berlin-Buch, Germany.
Max Planck Institute of Molecular Plant Physiology Golm, Germany.
Front Plant Sci. 2014 Mar 18;5:78. doi: 10.3389/fpls.2014.00078. eCollection 2014.
The plasma membrane is an important organelle providing structure, signaling and transport as major biological functions. Being composed of lipids and proteins with different physicochemical properties, the biological functions of membranes depend on specific protein-protein and protein-lipid interactions. Interactions of proteins with their specific sterol and lipid environment were shown to be important factors for protein recruitment into sub-compartmental structures of the plasma membrane. System-wide implications of altered endogenous sterol levels for membrane functions in living cells were not studied in higher plant cells. In particular, little is known how alterations in membrane sterol composition affect protein and lipid organization and interaction within membranes. Here, we conducted a comparative analysis of the plasma membrane protein and lipid composition in Arabidopsis sterol-biosynthesis mutants smt1 and ugt80A2;B1. smt1 shows general alterations in sterol composition while ugt80A2;B1 is significantly impaired in sterol glycosylation. By systematically analyzing different cellular fractions and combining proteomic with lipidomic data we were able to reveal contrasting alterations in lipid-protein interactions in both mutants, with resulting differential changes in plasma membrane signaling status.
质膜是一种重要的细胞器，具有结构、信号和运输等主要生物学功能。质膜由具有不同物理化学性质的脂质和蛋白质组成，其生物学功能取决于特定的蛋白质-蛋白质和蛋白质-脂质相互作用。已经表明，蛋白质与特定甾醇和脂质环境的相互作用是将蛋白质募集到质膜亚区室结构中的重要因素。在高等植物细胞中，尚未研究改变内源性甾醇水平对活细胞中膜功能的系统影响。特别是，对于改变膜甾醇组成如何影响膜内蛋白质和脂质的组织和相互作用，人们知之甚少。在这里，我们对拟南芥甾醇生物合成突变体 smt1 和 ugt80A2;B1 的质膜蛋白和脂质组成进行了比较分析。smt1 表现出甾醇组成的普遍改变，而 ugt80A2;B1 则在甾醇糖基化方面受到严重损害。通过系统地分析不同的细胞部分，并将蛋白质组学与脂质组学数据相结合，我们能够揭示这两个突变体中脂质-蛋白质相互作用的对比变化，从而导致质膜信号状态的差异变化。
