Arabidopsis Lunapark proteins are involved in ER cisternae formation
Arabidopsis Lunapark proteins are involved in ER cisternae formation
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DOI：
10.1101/256743
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发表时间：
2018-01
期刊：
影响因子：
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通讯作者：
V. Kriechbaumer;E. Breeze;Charlotte Pain;Frances Tolmie;L. Frigerio;C. Hawes
中科院分区：
文献类型：
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作者：
V. Kriechbaumer;E. Breeze;Charlotte Pain;Frances Tolmie;L. Frigerio;C. Hawes
植物内质网（ER）对维持细胞内稳态至关重要。内质网由一个动态和不断重塑的小管和池组成。一些保守的膜蛋白参与植物内质网的形成和维持，如RHD3和网状蛋白家族。尽管最近在哺乳动物和酵母细胞中进行了研究，但植物内质网组织的详细分子机制仍然很大程度上未知。最近在酵母和哺乳动物细胞中发现了一种名为Lunapark的新型内质网形成蛋白。在这里，我们鉴定了两个拟南芥LNP同源物，并通过共聚焦显微镜研究了它们的亚细胞定位，并使用蛋白质-蛋白质相互作用测定和突变分析研究了它们在形成内质网中的潜在功能。我们发现AtLNP1在烟叶表皮细胞中的过表达主要标记内质网的三向连接（琐事），而AtLNP2标记整个内质网。LNP蛋白的过表达导致内质网池丰度增加，lnp1lnp2 amiRNA系显示出结构较差的内质网网络。因此，我们假设AtLNP1和AtLNP2参与决定植物内质网的动态形态，可能通过调节内质网池的形成。
The plant endoplasmic reticulum (ER) is crucial to the maintenance of cellular homeostasis. The ER consists of a dynamic and continuously remodelling network of tubules and cisternae. Several conserved membrane proteins have been implicated in formation and maintenance of the ER network in plants, such as RHD3 and the reticulon family of proteins. Despite the recent work in mammalian and yeast cells, the detailed molecular mechanisms of ER network organisation in plants still remain largely unknown. Recently novel ER network-shaping proteins called Lunapark have been identified in yeast and mammalian cells. Here we identify two arabidopsis LNP homologues and investigate their subcellular localisation via confocal microscopy and potential function in shaping the ER network using protein-protein interaction assays and mutant analysis. We show that AtLNP1 overexpression in tobacco leaf epidermal cells mainly labels the three-way junctions (trivia) of the ER network whereas AtLNP2 labels the whole ER. Overexpression of LNP proteins results in an increased abundance of ER cisternae and an lnp1lnp2 amiRNA line displays a less structured ER network. Thus, we hypothesize that AtLNP1 and AtLNP2 are involved in determining the dynamic morphology of the plant ER, possibly by regulating the formation of ER cisternae.