Mouse lipogenic proteins promote the co-accumulation of triacylglycerols and sesquiterpenes in plant cells
Mouse lipogenic proteins promote the co-accumulation of triacylglycerols and sesquiterpenes in plant cells
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DOI：
10.1007/s00425-019-03148-9
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发表时间：
2019-07-01
期刊：
影响因子：
4.3
通讯作者：
Chapman, Kent D.
中科院分区：
文献类型：
--
作者：
Cai, Yingqi;Whitehead, Payton;Chapman, Kent D.
主要结论小鼠FIT 2蛋白将细胞质萜类生物合成机制重定向至ER中的脂滴形成结构域，这种重定位支持植物细胞中萜类的有效区室化和积累。小鼠（Mus musculus）脂肪储存诱导跨膜蛋白2（MmFIT 2），一种在哺乳动物的脂滴（LD）生物发生中具有重要作用的内质网（ER）驻留蛋白，可以在植物细胞中起促进中性脂质区室化的作用。令人惊讶的是，在亲和捕获实验中，本氏烟草5-表-马兜铃烯合酶（NbEAS），一种可溶性细胞质定位的倍半萜合酶，是在烟草中瞬时表达测定中与GFP标记的MmFIT 2共沉淀的最丰富的蛋白质之一。本生叶。与下拉实验的结果一致，仅当与MmFIT 2共表达时，mCherry标记的NbEAS的亚细胞位置从细胞质改变为ER中的LD形成结构域。NbEAS和MmFIT 2与小鼠二酰基甘油：酰基-CoA酰基转移酶2（MmDGAT 2）在N.本塞姆氏菌叶显著增加了细胞质LD的数量，并支持倍半萜、5-表-马兜铃烯和辣椒二醇的积累，高达单独农杆菌感染引起的水平的10倍。两者合计，我们的研究结果表明，MmFIT 2招聘倍半萜合成机制参与LD形成的ER亚结构域，这个过程可以提高植物细胞中倍半萜生物合成和区室化的效率。此外，MmFIT 2和MmDGAT 2代表跨界脂肪生成蛋白因子，其可用于在植物营养组织的细胞质中更广泛地工程化萜烯积累。
Main conclusionMouse FIT2 protein redirects the cytoplasmic terpene biosynthetic machinery to lipid-droplet-forming domains in the ER and this relocalization supports the efficient compartmentalization and accumulation of sesquiterpenes in plant cells.Mouse (Mus musculus) fat storage-inducing transmembrane protein 2 (MmFIT2), an endoplasmic reticulum (ER)-resident protein with an important role in lipid droplet (LD) biogenesis in mammals, can function in plant cells to promote neutral lipid compartmentalization. Surprisingly, in affinity capture experiments, the Nicotiana benthamiana 5-epi-aristolochene synthase (NbEAS), a soluble cytoplasm-localized sesquiterpene synthase, was one of the most abundant proteins that co-precipitated with GFP-tagged MmFIT2 in transient expression assays in N. benthamiana leaves. Consistent with results of pull-down experiments, the subcellular location of mCherry-tagged NbEAS was changed from the cytoplasm to the LD-forming domains in the ER, only when co-expressed with MmFIT2. Ectopic co-expression of NbEAS and MmFIT2 together with mouse diacylglycerol:acyl-CoA acyltransferase 2 (MmDGAT2) in N. benthamiana leaves substantially increased the numbers of cytoplasmic LDs and supported the accumulation of the sesquiterpenes, 5-epi-aristolochene and capsidiol, up to tenfold over levels elicited by Agrobacterium infection alone. Taken together, our results suggest that MmFIT2 recruits sesquiterpene synthetic machinery to ER subdomains involved in LD formation and that this process can enhance the efficiency of sesquiterpene biosynthesis and compartmentalization in plant cells. Further, MmFIT2 and MmDGAT2 represent cross-kingdom lipogenic protein factors that may be used to engineer terpene accumulation more broadly in the cytoplasm of plant vegetative tissues.