Toxplasma gondii wild-type vs. ASH4 knockout untargeted metabolomics raw data

The intracellular protozoan parasite Toxoplasma gondii must scavenge cholesterol and other lipids from the host to facilitate intracellular growth and replication. Enzymes responsible for neutral lipid synthesis have been identified but there is no evidence for enzymes that catalyze lipolysis of cholesterol esters and esterified lipids. Here we characterize several T. gondii serine hydrolases with esterase and thioesterase activities that were previously thought to be depalmitoylating enzymes. We find they do not cleave palmitoyl thiol esters but rather hydrolyze short chain lipid esters. Deletion of one of the hydrolases results in alterations in levels of multiple lipids species. We also identify small molecule inhibitors of these hydrolases and show that treatment of parasites results in phenotypic defects reminiscent of parasites exposed to excess cholesterol or oleic acid. Together, these data characterize enzymes necessary for processing lipids critical for infection and highlight...

细胞内原生动物寄生虫刚地弓形虫（Toxoplasma gondii）必须从宿主处摄取胆固醇及其他脂质，以支持胞内生长与增殖。目前已鉴定出负责中性脂质合成的酶，但尚未发现能够催化胆固醇酯与酯化脂质脂解的酶类。本研究对数种弓形虫丝氨酸水解酶（serine hydrolases）进行了表征，这类酶曾被认为是去棕榈酰化酶，兼具酯酶与硫酯酶活性。我们发现其并不能裂解棕榈酰硫酯，反而可水解短链脂质酯。对其中一种水解酶进行基因缺失后，会导致多种脂质物种的水平发生改变。本研究还鉴定出了这类水解酶的小分子抑制剂，并证实对寄生虫施加此类抑制剂会引发表型缺陷，其表型与暴露于过量胆固醇或油酸的寄生虫相似。综上，本研究表征了对感染至关重要的脂质加工所需酶类，并揭示了……