College of Animal Science and Technology, Shandong Agricultural University, Tai'an 271018, China.
Int J Mol Sci. 2023 Jan 20;24(3):2096. doi: 10.3390/ijms24032096.
Lipophagy plays an important role in regulating lipid metabolism in mammals. The exact function of autophagy-related protein 2 (Atg2) has been investigated in mammals, but research on the existence and functions of Atg2 in (AmAtg2) is still limited. Here, autophagy occurred in honeybee pupae, which targeted lipid droplets (LDs) in fat body, namely lipophagy, which was verified by co-localization of LDs with microtubule-associated protein 1A/1B light chain 3 beta (LC3). Moreover, AmAtg2 homolog B (AmAtg2B) was expressed specifically in pupal fat body, which indicated that AmAtg2B might have special function in fat body. Further, AmAtg2B antibody neutralization and AmAtg2B knock-down were undertaken to verify the functions in pupae. Results showed that low expression of AmAtg2B at the protein and transcriptional levels led to lipophagy inhibition, which down-regulated the expression levels of proteins and genes related to lipolysis. Altogether, results in this study systematically revealed that AmAtg2B interfered with lipophagy and then caused abnormal lipolysis in the pupal stage.
脂噬作用在哺乳动物的脂质代谢调节中起着重要作用。在哺乳动物中已经研究了自噬相关蛋白 2(Atg2)的确切功能,但关于 Atg2 在 (AmAtg2)中的存在和功能的研究仍然有限。在这里,在蜜蜂蛹中发生了自噬,即靶向脂肪体中脂滴(LDs)的脂噬,这通过 LDs 与微管相关蛋白 1A/1B 轻链 3β(LC3)的共定位得到验证。此外,AmAtg2 同源物 B(AmAtg2B)特异性在蛹脂肪体中表达,这表明 AmAtg2B 可能在脂肪体中具有特殊功能。此外,进行了 AmAtg2B 抗体中和和 AmAtg2B 敲低实验,以验证其在蛹中的功能。结果表明,AmAtg2B 在蛋白质和转录水平上的低表达导致脂噬作用抑制,从而下调了与脂肪分解相关的蛋白质和基因的表达水平。总之,本研究系统地揭示了 AmAtg2B 干扰脂噬作用,然后导致蛹期异常脂肪分解。