Institute of Microbial Chemistry (BIKAKEN), Tokyo, Japan.
Genes Cells. 2020 Jan;25(1):65-70. doi: 10.1111/gtc.12733. Epub 2019 Dec 1.
Atg2 is one of the essential factors for autophagy. Recent advance of structural and biochemical study on yeast Atg2 proposed that Atg2 tethers the edge of the isolation membrane (IM) to the endoplasmic reticulum and mediates direct lipid transfer (LT) from ER to IM for IM expansion. In mammals, two Atg2 orthologs, ATG2A and ATG2B, participate in autophagic process. Here we showed that human ATG2B possesses the membrane tethering (MT) and LT activity that was promoted by negatively charged membranes and an Atg18 ortholog WIPI4. By contrast, negatively charged membranes reduced the yeast Atg2 activities in the absence of Atg18. These results suggest that the MT/LT activity of Atg2 is evolutionally conserved although their regulation differs among species.
Atg2 是自噬作用的必需因素之一。最近对酵母 Atg2 的结构和生化研究的进展表明，Atg2 将隔离膜 (IM) 的边缘与内质网连接起来，并介导 ER 到 IM 的直接脂质转移 (LT)，以促进 IM 的扩展。在哺乳动物中，两种 Atg2 同源物 ATG2A 和 ATG2B 参与自噬过程。在这里，我们表明人类 ATG2B 具有膜连接 (MT) 和 LT 活性，该活性由带负电荷的膜和 Atg18 同源物 WIPI4 促进。相比之下，在没有 Atg18 的情况下，带负电荷的膜降低了酵母 Atg2 的活性。这些结果表明，尽管不同物种的调控方式不同，但 Atg2 的 MT/LT 活性在进化上是保守的。
