溶酶体稳态的调控机制研究

溶酶体是细胞内物质降解的主要细胞器，也是细胞生长和代谢的重要信号汇集地。溶酶体稳态维持是指细胞在响应外界信号或应激时，对溶酶体的生成、内部酸性环境、外膜完整性等的维持和适应性调整。溶酶体稳态破坏导致多种重大疾病，其调控机制亟待深入阐明。本项目旨在利用诱导溶酶体生成或抑制溶酶体酸化的天然化合物为探针，确定它们特异性发挥作用的信号通路，鉴定化合物作用的靶蛋白，研究小分子化合物对其作用的信号通路中的蛋白质互作，蛋白质修饰及信号传递的影响，从而揭示溶酶体稳态维持的两个重要方面：溶酶体生成和溶酶体酸化调控的新机制。我们还建立了基于CRISPR/Cas9的筛选系统，用于鉴定诱导溶酶体生成的化合物发挥作用的信号通路，并筛选溶酶体基因转录的调控因子。我们相信，综合利用小分子天然化合物、遗传筛选、蛋白追踪定位、活细胞成像、蛋白质修饰和蛋白质互作等多种研究手段，本项研究将深入揭示溶酶体稳态维持的重要调控机制。

Lysosomes are the major degradation and signaling centers within the cell. Lysosomes respond to environmental cues by controlling their own biogenesis, low pH value and membrane integrity, thus maintaining their homeostasis. Disruption of lysosomal homeostasis leads to many severe human diseases, including lysosomal storage disorders (LSDs), neurodegenerative diseases and cancer. The mechanisms underlying lysosomal homeostasis are, however, poorly understood. In this project, we aim to dissect novel mechanisms governing lysosome biogenesis and lysosome acidification, two essential aspects for maintenance of lysosomal homeostasis. We have identified unique natural small-molecule compounds that can induce lysosome biogenesis or increase lysosomal pH value. We plan to further investigate how these compounds function within the cell by identifying their target proteins and signaling pathways, using a combination of approaches including protein-protein interactions, live-cell imaging, protein modifications, and chemical modification of compounds. Meanwhile, we have established a CRISPR/Cas9-based system to identify regulators of transcription of lysosomal genes, and to identify the signaling pathways in which the aforementioned natural small-molecule compounds play their roles. This unique research will not only provide important novel insights into lysosomal homeostasis, but also reveal pathological mechanisms underlying lysosome-related human diseases.