中国科学院植物研究所张立新团队发现,液液相转换驱动叶绿体内蛋白分选。相关论文于2020年3月12日在线发表于国际学术期刊《细胞》。
Title: Liquid-Liquid Phase Transition Drives Intra-chloroplast Cargo Sorting
Author: Min Ouyang, Xiaoyi Li, Jing Zhang, Peiqiang Feng, Hua Pu, Lingxi Kong, Zechen Bai, Liwei Rong, Xiumei Xu, Wei Chi, Qiang Wang, Fan Chen, Congming Lu, Jianren Shen, Lixin Zhang
Issue&Volume: 2020-03-12
Abstract: In eukaryotic cells, organelle biogenesis is pivotal for cellular function and cellsurvival. Chloroplasts are unique organelles with a complex internal membrane network.The mechanisms of the migration of imported nuclear-encoded chloroplast proteins acrossthe crowded stroma to thylakoid membranes are less understood. Here, we identifiedtwo Arabidopsis ankyrin-repeat proteins, STT1 and STT2, that specifically mediate sorting of chloroplasttwin arginine translocation (cpTat) pathway proteins to thylakoid membranes. STT1and STT2 form a unique hetero-dimer through interaction of their C-terminal ankyrindomains. Binding of cpTat substrate by N-terminal intrinsically disordered regionsof STT complex induces liquid-liquid phase separation. The multivalent nature of STToligomer is critical for phase separation. STT-Hcf106 interactions reverse phase separationand facilitate cargo targeting and translocation across thylakoid membranes. Thus,the formation of phase-separated droplets emerges as a novel mechanism of intra-chloroplastcargo sorting. Our findings highlight a conserved mechanism of phase separation inregulating organelle biogenesis.
DOI: 10.1016/j.cell.2020.02.045
Source: https://www.cell.com/cell/fulltext/S0092-8674(20)30222-1