Synergistic roles of acyl-CoA binding protein (ACBP1) and sterol carrier protein 2 (SCP2) in Toxoplasma lipid metabolism
Synergistic roles of acyl-CoA binding protein (ACBP1) and sterol carrier protein 2 (SCP2) in Toxoplasma lipid metabolism
复制标题
酰基辅酶A结合蛋白（ACBP1）和甾醇载体蛋白2（SCP2）在弓形虫脂质代谢中的协同作用
DOI：
10.1111/cmi.12970
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发表时间：
2019-03-01
影响因子：
3.4
通讯作者：
Liu, Qun
中科院分区：
文献类型：
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作者：
Fu, Yong;Cui, Xia;Liu, Qun
弓形虫依赖于顶体定位的FASII途径和内质网相关的脂肪酸延伸途径来合成脂肪酸，这些脂肪酸主要以长链酰基辅酶A(LCACoA)酯的形式通过脂类代谢流动。弓形虫酰基辅酶A转运体在脂类代谢中的作用尚不清楚。在这里，我们研究了酰基辅酶A结合蛋白(TgACBP1)和甾醇载体蛋白-2(TgSCP2)作为胞内酰辅酶A转运体在脂质代谢中的作用。荧光结合实验和酵母互补实验分别证实了TgACBP1和TgSCP2的酰基辅酶A结合活性。TgACBP1或TgSCP2的破坏都不会引起明显的表型变化，而双重破坏会导致细胞内生长和对小鼠毒力的缺陷。气相色谱-质谱联用(GC-MS)结果表明，TgACBP1或TgSCP2单独干扰导致C18：1丰度降低，而双重干扰导致C18：1、C22：1和C24：1丰度降低。C-13标记结合GC-MS分析表明，TgACBP1和TgSCP2双干扰导致C18：0、C22：1和C24：1合成速率降低。此外，高效液相色谱-高分辨质谱仪(HPLC-HRMS)用于寄生虫脂肪组学分析，表明TgACBP1和TgSCP2丢失导致甘油和磷脂合成严重缺陷。总之，TgACBP1和TgSCP2在弓形虫的脂代谢中起着协同作用。
Toxoplasma gondii relies on apicoplast-localised FASII pathway and endoplasmic reticulum-associated fatty acid elongation pathway for the synthesis of fatty acids, which flow through lipid metabolism mainly in the form of long-chain acyl-CoA (LCACoAs) esters. Functions of Toxoplasma acyl-CoA transporters in lipid metabolism remain unclear. Here, we investigated the roles of acyl-CoA-binding protein (TgACBP1) and a sterol carrier protein-2 (TgSCP2) as cytosolic acyl-CoA transporters in lipid metabolism. The fluormetric binding assay and yeast complementation confirmed the acyl-CoA binding activities of TgACBP1 and TgSCP2, respectively. Disruption of either TgACBP1 or TgSCP2 caused no obviously phenotypic changes, whereas double disruption resulted in defects in intracellular growth and virulence to mice. Gas chromatography coupled with mass spectrometry (GC-MS) results showed that TgACBP1 or TgSCP2 disruption alone led to decreased abundance of C18:1, whereas double disruption resulted in reduced abundance of C18:1, C22:1, and C24:1. C-13 labelling assay combined with GC-MS showed that double disruption of TgACBP1 and TgSCP2 led to reduced synthesis rates of C18:0, C22:1, and C24:1. Furthermore, high performance liquid chromatography coupled with high resolution mass spectrometry (HPLC-HRMS) was used for lipidomic analysis of parasites and indicated that loss of TgACBP1 and TgSCP2 caused serious defects in production of glycerides and phospholipids. Collectively, TgACBP1 and TgSCP2 play synergistic roles in lipid metabolism in T. gondii.