Identification of a New Class of Lipid Droplet-Associated Proteins in Plants
Identification of a New Class of Lipid Droplet-Associated Proteins in Plants
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DOI：
10.1104/pp.113.222455
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发表时间：
2013-08-01
期刊：
影响因子：
7.4
通讯作者：
Chapman, Kent D.
中科院分区：
文献类型：
--
作者：
Horn, Patrick J.;James, Christopher N.;Chapman, Kent D.
植物中的脂滴（也被称为油体、脂体或油小体）在种子中有很好的特征，而与它们表面相关的主要蛋白质油蛋白被证明在种子干燥和再水化过程中对稳定脂滴很重要。然而，脂滴基本上存在于所有植物细胞类型中，其中许多细胞可能不需要油蛋白介导的稳定。与非种子脂滴表面相关的蛋白质，可能影响这个隔室的形成、稳定性和周转，仍有待阐明。在这里，我们结合了鳄梨（Persea americana）中果皮的脂质组学、蛋白质组学和转录组学研究，鉴定了两种新的脂滴相关蛋白，我们将其命名为LDAP1和LDAP2。这些蛋白质彼此之间高度相似，也与橡胶生产植物中积累的小橡胶颗粒蛋白质非常相似。与LDAP1和LDAP2同源的拟南芥（Arabidopsis thaliana）基因At3g05500在诱导积累甘油三酯的烟草（Nicotiana tabacum）细胞中短暂表达后，定位于脂滴表面。我们提出，小的橡胶颗粒蛋白样蛋白参与了植物细胞细胞质中富含脂质颗粒的结合和稳定的一般过程，而鳄梨和拟南芥蛋白成员揭示了参与植物组织中三酰基甘油包装的细胞机制的一个新方面。脂质
Lipid droplets in plants (also known as oil bodies, lipid bodies, or oleosomes) are well characterized in seeds, and oleosins, the major proteins associated with their surface, were shown to be important for stabilizing lipid droplets during seed desiccation and rehydration. However, lipid droplets occur in essentially all plant cell types, many of which may not require oleosin-mediated stabilization. The proteins associated with the surface of nonseed lipid droplets, which are likely to influence the formation, stability, and turnover of this compartment, remain to be elucidated. Here, we have combined lipidomic, proteomic, and transcriptomic studies of avocado (Persea americana) mesocarp to identify two new lipid droplet-associated proteins, which we named LDAP1 and LDAP2. These proteins are highly similar to each other and also to the small rubber particle proteins that accumulate in rubber-producing plants. An Arabidopsis (Arabidopsis thaliana) homolog to LDAP1 and LDAP2, At3g05500, was localized to the surface of lipid droplets after transient expression in tobacco (Nicotiana tabacum) cells that were induced to accumulate triacylglycerols. We propose that small rubber particle protein-like proteins are involved in the general process of binding and perhaps the stabilization of lipid-rich particles in the cytosol of plant cells and that the avocado and Arabidopsis protein members reveal a new aspect of the cellular machinery that is involved in the packaging of triacylglycerols in plant tissues. Lipid