Imamura Sousuke, Kawase Yasuko, Kobayashi Ikki, Shimojima Mie, Ohta Hiroyuki, Tanaka Kan
a Chemical Resources Laboratory, Tokyo Institute of Technology , Yokohama , Japan.
b Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST) , Saitama , Japan.
Plant Signal Behav. 2016;11(3):e1149285. doi: 10.1080/15592324.2016.1149285.
Most microalgae abundantly accumulate lipid droplets (LDs) containing triacylglycerols (TAGs) under several stress conditions, but the underlying molecular mechanism of this accumulation remains unclear. In a recent study, we found that inhibition of TOR (target of rapamycin), a highly conserved protein kinase of eukaryotes, by rapamycin resulted in TAG accumulation in microalgae, indicating that TOR negatively regulates TAG accumulation. Here, we show that formation of intracellular LDs and TAG accumulation were also induced in the unicellular green alga Chlamydomonas reinhardtii after exposure to Torin1 or AZD8055, which are novel TOR inhibitors that inhibit TOR activity in a manner different from rapamycin. These results supported quite well our previous conclusion that TOR is a central regulator of TAG accumulation in microalgae.
在多种胁迫条件下，大多数微藻会大量积累含有三酰甘油（TAGs）的脂滴（LDs），但其积累的潜在分子机制仍不清楚。在最近的一项研究中，我们发现雷帕霉素抑制真核生物中高度保守的蛋白激酶TOR（雷帕霉素靶蛋白）会导致微藻中TAG积累，这表明TOR对TAG积累起负调控作用。在此，我们表明，单细胞绿藻莱茵衣藻在暴露于Torin1或AZD8055（新型TOR抑制剂，其抑制TOR活性的方式与雷帕霉素不同）后，也会诱导细胞内LDs的形成和TAG积累。这些结果很好地支持了我们之前的结论，即TOR是微藻中TAG积累的核心调节因子。
