Arabidopsis Sec14 proteins (SFH5 and SFH7) mediate interorganelle transport of phosphatidic acid and regulate chloroplast development.
Arabidopsis Sec14 proteins (SFH5 and SFH7) mediate interorganelle transport of phosphatidic acid and regulate chloroplast development.
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拟南芥 Sec14 蛋白（SFH5 和 SFH7）介导磷脂酸的细胞器间转运并调节叶绿体发育
DOI：
10.1073/pnas.2221637120
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发表时间：
2023-02-07
影响因子：
11.1
通讯作者：
Xue, Hong -Wei
中科院分区：
文献类型：
--
作者：
Yao, Hong-Yan;Lu, Yao-Qi;Yang, Xiao-Li;Wang, Xiao-Qing;Luo, Zhipu;Lin, De -Li;Wu, Jia-Wei;Xue, Hong -Wei
太阳能在真核光合生物的类囊体膜上转化为化学能，而类囊体膜上适当的脂质组装，特别是来自其他细胞器的脂质前体的转移是至关重要的。Sec14同源蛋白在所有真核生物中都被鉴定出来，它可以结合和转移多种脂质。通过拟南芥Sec14同源蛋白5 （AtSFH5）的Sec14结构域的结晶及相关的生化和遗传学研究，我们阐明了磷脂酸（PA）的特定结合模式和植物Sec14结构域的独特结构特征，并论证了AtSFH5和AtSFH7在调控叶绿体发育中的重要作用，为细胞器间磷脂转运提供了模型和参与细胞质体适应性进化的机制。在真核光合生物中，脂质在叶绿体中形成了特化的类囊体膜，而脂质从其他细胞器向叶绿体转移的分子基础还有待进一步阐明。本研究揭示了拟南芥Sec14同源蛋白AtSFH5和AtSFH7在磷脂酸（PA）从内质网（ER）向叶绿体转移中的结构基础，以及调节叶绿体脂质组成和类囊体发育的功能。AtSFH5和AtSFH7定位于内质网和叶绿体，其缺失导致叶绿体结构异常和堆叠类囊体膜厚度减少。我们证明了AtSFH5，而不是酵母和人Sec14蛋白，可以特异性地识别和转移PA。AtSFH5- sec14结构域与L-α-磷脂酸（L-α-PA）和1,2-二棕榈酰基-sn-甘油-3-磷酸（DPPA）配合物的晶体结构表明，两个PA配体以不同的构型依偎在中心腔中，阐明了PA与AtSFH5的特异性结合模式，不同于以往报道的磷脂酰乙醇胺(PE)/磷脂酰胆碱(PC)/磷脂酰肌醇（PI）的结合模式。定量脂质组学分析显示，在缺乏AtSFH5和AtSFH7的情况下，PA和单半乳糖二酰基甘油（MGDG），特别是MGDG sn-2位置的C18脂肪酸显著降低，表明er到质体（叶绿体）的脂质转移中断。我们的研究确定了植物SFH蛋白在细胞器间传递PA的作用并阐明了其结构基础，并提出了一种源自蓝细菌内共生的ER-叶绿体胞间磷脂从内质网转运到叶绿体的模型，提供了一种参与细胞质体适应性进化的机制。
Solar is converted to chemical energy at thylakoid membranes of eukaryotic photosynthetic organisms, and proper lipid assembly in thylakoid membrane, particularly the transfer of lipid precursors from other organelles, is crucial. Sec14 homology proteins are identified in all eukaryotes, which can bind and transfer a wide range of lipids. By crystallizing the Sec14 domain of Arabidopsis Sec14 homology protein5 (AtSFH5) and relevant biochemical and genetic studies, we elucidated the specific binding modes of phosphatidic acid (PA) and unique structural features of plant Sec14 domains, and demonstrated the crucial roles of AtSFH5 and AtSFH7 in regulating chloroplast development providing a model for interorganelle phospholipid transport and a mechanism involving in the adaptive evolution of cellular plastids. Lipids establish the specialized thylakoid membrane of chloroplast in eukaryotic photosynthetic organisms, while the molecular basis of lipid transfer from other organelles to chloroplast remains further elucidation. Here we revealed the structural basis of Arabidopsis Sec14 homology proteins AtSFH5 and AtSFH7 in transferring phosphatidic acid (PA) from endoplasmic reticulum (ER) to chloroplast, and whose function in regulating the lipid composition of chloroplast and thylakoid development. AtSFH5 and AtSFH7 localize at both ER and chloroplast, whose deficiency resulted in an abnormal chloroplast structure and a decreased thickness of stacked thylakoid membranes. We demonstrated that AtSFH5, but not yeast and human Sec14 proteins, could specifically recognize and transfer PA in vitro. Crystal structures of the AtSFH5-Sec14 domain in complex with L-α-phosphatidic acid (L-α-PA) and 1,2-dipalmitoyl-sn-glycero-3-phosphate (DPPA) revealed that two PA ligands nestled in the central cavity with different configurations, elucidating the specific binding mode of PA to AtSFH5, different from the reported phosphatidylethanolamine (PE)/phosphatidylcholine (PC)/phosphatidylinositol (PI) binding modes. Quantitative lipidomic analysis of chloroplast lipids showed that PA and monogalactosyldiacylglycerol (MGDG), particularly the C18 fatty acids at sn-2 position in MGDG were significantly decreased, indicating a disrupted ER-to-plastid (chloroplast) lipid transfer, under deficiency of AtSFH5 and AtSFH7. Our studies identified the role and elucidated the structural basis of plant SFH proteins in transferring PA between organelles, and suggested a model for ER-chloroplast interorganelle phospholipid transport from inherent ER to chloroplast derived from endosymbiosis of a cyanobacteriumproviding a mechanism involved in the adaptive evolution of cellular plastids.
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DOI：
10.1073/pnas.100132197
发表时间：
2000-07-05
影响因子：
11.1
作者：
Jarvis, P;Dörmann, P;Chory, J
通讯作者：
Chory, J
DOI：
10.1073/pnas.1609184113
发表时间：
2016-09-20
影响因子：
11.1
作者：
Kelly, Amelie A.;Kalisch, Barbara;Doermann, Peter
通讯作者：
Doermann, Peter
影响因子：
3.3
作者：
Ghosh R;de Campos MK;Huang J;Huh SK;Orlowski A;Yang Y;Tripathi A;Nile A;Lee HC;Dynowski M;Schäfer H;Róg T;Lete MG;Ahyayauch H;Alonso A;Vattulainen I;Igumenova TI;Schaaf G;Bankaitis VA
通讯作者：
Bankaitis VA
影响因子：
56.9
作者：
Dörmann, P;Balbo, I;Benning, C
通讯作者：
Benning, C
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K