Geng Jiefei, Baba Misuzu, Nair Usha, Klionsky Daniel J
Life Sciences Institute and Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
J Cell Biol. 2008 Jul 14;182(1):129-40. doi: 10.1083/jcb.200711112.
In yeast, approximately 31 autophagy-related (Atg) proteins have been identified. Most of them reside at the phagophore assembly site (PAS), although the function of the PAS mostly remains unclear. One reason for the latter is the lack of stoichiometric information regarding the Atg proteins at this site. We report the application of fluorescence microscopy to study the amount of Atg proteins at the PAS. We find that an increase in the amount of Atg11 at the PAS enhances the recruitment of Atg8 and Atg9 to this site and facilitates the formation of more cytoplasm-to-vacuole targeting vesicles. In response to autophagy induction, the amount of most Atg proteins remains unchanged at the PAS, whereas we see an enhanced recruitment of Atg8 and 9 at this site. During autophagy, the amount of Atg8 at the PAS showed a periodic change, indicating the formation of autophagosomes. Application of this method and further analysis will provide more insight into the functions of Atg proteins.
在酵母中，已鉴定出约31种自噬相关（Atg）蛋白。它们中的大多数位于吞噬泡组装位点（PAS），尽管PAS的功能大多仍不清楚。后者的一个原因是缺乏关于该位点Atg蛋白的化学计量信息。我们报告了应用荧光显微镜来研究PAS处Atg蛋白的数量。我们发现PAS处Atg11数量的增加会增强Atg8和Atg9向该位点的募集，并促进更多细胞质到液泡靶向囊泡的形成。响应自噬诱导，大多数Atg蛋白在PAS处的数量保持不变，而我们在此位点看到Atg8和Atg9的募集增强。在自噬过程中，PAS处Atg8的数量呈现周期性变化，表明自噬体的形成。应用此方法并进行进一步分析将为Atg蛋白的功能提供更多见解。
