Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, PR China.
Jiangsu Vocational College of Agriculture and Forestry, Jurong, 212400, Jiangsu, PR China.
Phytochemistry. 2020 Apr;172:112283. doi: 10.1016/j.phytochem.2020.112283. Epub 2020 Feb 5.
Ceramide synthases (CERSs) catalyse an N-acyltransferase reaction using long-chain base (LCB) and fatty acyl-coenzyme A (CoA) as substrates to synthesize ceramide (Cer), which is the backbone of all complex sphingolipids. In the present study, three CERSs (LAG1, LAG2 and LAG3) form Ganoderma lucidum were analysed. The silencing of lag1 by RNA interference reduced ganoderic acid biosynthesis and Cer and complex sphingolipids contents, which contain long-chain-fatty-acids (LCFAs, including C16 and C18). In contrast, the silencing of lag2 or lag3 did not result in obvious phenotypic and sphingolipid homeostasis changes, although the lag2/lag3 double-silenced mutants exhibited increased ganoderic acid biosynthesis as well as reduced growth, reduced Cer and complex sphingolipids contents, which contain very-long-chain fatty acids (VLCFAs, including C22, C24 and C26). The results of the present study indicate that the three assayed CERSs have distinct physiological functions and substrate specificities in G. lucidum.
神经酰胺合酶（CERSs）以长链碱基（LCB）和长链脂肪酸辅酶 A（CoA）作为底物，催化 N-酰基转移酶反应，合成神经酰胺（Cer），这是所有复杂神经鞘脂的骨架。本研究分析了三种来自灵芝的 CERS（LAG1、LAG2 和 LAG3）。通过 RNA 干扰沉默 lag1 会减少灵芝酸生物合成以及 Cer 和复杂神经鞘脂的含量，这些物质含有长链脂肪酸（LCFAs，包括 C16 和 C18）。相比之下，沉默 lag2 或 lag3 并不会导致明显的表型和神经鞘脂动态平衡变化，尽管 lag2/lag3 双沉默突变体表现出增加的灵芝酸生物合成以及生长减少、Cer 和复杂神经鞘脂含量降低，这些物质含有非常长链脂肪酸（VLCFAs，包括 C22、C24 和 C26）。本研究结果表明，在所检测的三种 CERSs 在灵芝中具有不同的生理功能和底物特异性。
