SEIPIN Isoforms Interact with the Membrane-Tethering Protein VAP27-1 for Lipid Droplet Formation[OPEN]
SEIPIN Isoforms Interact with the Membrane-Tethering Protein VAP27-1 for Lipid Droplet Formation[OPEN]
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DOI：
10.1105/tpc.19.00771
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发表时间：
2020-09-01
期刊：
影响因子：
11.6
通讯作者：
Chapman, Kent D.
中科院分区：
文献类型：
--
作者：
Greer, Michael Scott;Cai, Yingqi;Chapman, Kent D.
参与脂滴（LD）生物发生的两种ER驻留的SEIPIN同种型与膜系留蛋白VAP 27 -1相互作用，特别是通过它们的N末端，并在LD形成中合作。与具有单一SEIPIN基因的动物和酵母细胞不同，植物具有由不同基因编码的三种不同的SEIPIN同种型。SEIPIN作用的机制仍然知之甚少，在这里，我们证明了拟南芥（Arabidopsis thaliana）中两种SEIPIN亚型AtSEIPIN 2和AtSEIPIN 3的部分功能可能取决于它们与囊泡相关膜蛋白（VAMP）相关蛋白（VAP）家族成员AtVAP 27 -1的相互作用。VAP在ER和其他细胞器之间的膜接触位点的形成和脂质转移中具有公认的作用，在这里，我们结合生物化学、细胞生物学和遗传学方法表明AtVAP 27 -1与AtSEIPIN的N末端相互作用2和AtSEIPIN 3并可能支持LD的正常形成。这一发现表明，植物细胞中的内质网膜束缚机制可能与内质网LD生物发生中的选择SEIPIN亚型一起发挥作用，并且在酵母菌中的额外实验证据支持这种相互作用在其他真核系统中可能很重要的可能性。
Two ER-resident SEIPIN isoforms involved in lipid droplet (LD) biogenesis interact with the membrane tethering protein VAP27-1, specifically through their N termini, and cooperate in LD formation.SEIPIN proteins are localized to endoplasmic reticulum (ER)-lipid droplet (LD) junctions where they mediate the directional formation of LDs into the cytoplasm in eukaryotic cells. Unlike in animal and yeast cells, which have single SEIPIN genes, plants have three distinct SEIPIN isoforms encoded by separate genes. The mechanism of SEIPIN action remains poorly understood, and here we demonstrate that part of the function of two SEIPIN isoforms in Arabidopsis (Arabidopsis thaliana), AtSEIPIN2 and AtSEIPIN3, may depend on their interaction with the vesicle-associated membrane protein (VAMP)-associated protein (VAP) family member AtVAP27-1. VAPs have well-established roles in the formation of membrane contact sites and lipid transfer between the ER and other organelles, and here, we used a combination of biochemical, cell biology, and genetics approaches to show that AtVAP27-1 interacts with the N termini of AtSEIPIN2 and AtSEIPIN3 and likely supports the normal formation of LDs. This insight indicates that the ER membrane tethering machinery in plant cells could play a role with select SEIPIN isoforms in LD biogenesis at the ER, and additional experimental evidence inSaccharomyces cerevisiaesupports the possibility that this interaction may be important in other eukaryotic systems.