研究人员表明过氧物酶体的导入与核运输相似。过氧体膜蛋白PEX13含有一个保守的富含酪氨酸（Y）和甘氨酸（G）的YG结构域，它形成了一个类似于核孔内苯丙氨酸-甘氨酸（FG）重复形成的选择性状态。PEX13以两个方向驻留在膜上，这两个方向使YG网状结构低聚并悬浮在脂质双分子层内。纯化的YG结构域形成水凝胶，PEX5通过使用保守的芳香族氨基酸模体来选择性地将货物带入其中。因此，YG网状结构形成一个水通道，而PEX5通过该通道将折叠的蛋白质送入过氧体。
据介绍，过氧化物酶体是无处不在的细胞器，其功能障碍导致致命的人类疾病。大多数过氧化物酶体的蛋白质是由可溶性受体PEX5以折叠状态从细胞膜导入的。折叠的货物是如何穿过膜的尚不清楚。
附：英文原文
Title: Protein import into peroxisomes occurs through a nuclear pore–like phase
Author: Yuan Gao, Michael L. Skowyra, Peiqiang Feng, Tom A. Rapoport
Issue&Volume: 2022-12-16
Abstract: Peroxisomes are ubiquitous organelles whose dysfunction causes fatal human diseases. Most peroxisomal proteins are imported from the cytosol in a folded state by the soluble receptor PEX5. How folded cargo crosses the membrane is unknown. Here, we show that peroxisomal import is similar to nuclear transport. The peroxisomal membrane protein PEX13 contains a conserved tyrosine (Y)– and glycine (G)–rich YG domain, which forms a selective phase resembling that formed by phenylalanine-glycine (FG) repeats within nuclear pores. PEX13 resides in the membrane in two orientations that oligomerize and suspend the YG meshwork within the lipid bilayer. Purified YG domains form hydrogels into which PEX5 selectively partitions, by using conserved aromatic amino acid motifs, bringing cargo along. The YG meshwork thus forms an aqueous conduit through which PEX5 delivers folded proteins into peroxisomes.
DOI: adf3971
Source: https://www.science.org/doi/10.1126/science.adf3971