A Role for the Peroxin Pex8p in Pex20p-dependent Thiolase Import into Peroxisomes of the Yeast Yarrowia lipolytica *
A Role for the Peroxin Pex8p in Pex20p-dependent Thiolase Import into Peroxisomes of the Yeast Yarrowia lipolytica *
复制标题
过氧化物酶 Pex8p 在 Pex20p 依赖性硫解酶导入解脂耶氏酵母过氧化物酶体中的作用 *
DOI：
10.1074/jbc.m005072200
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
R. A. Rachubinski
中科院分区：
文献类型：
--
作者：
Jennifer J. Smith;R. A. Rachubinski
过氧化物酶是过氧化物酶体组装所需的蛋白质。胞质过氧化物蛋白 Pex20p 直接与 β-氧化酶硫解酶结合，是其二聚化和过氧化物酶体靶向所必需的。过氧化物酶体内过氧化物蛋白 Pex8p 在过氧化物酶体基质蛋白（包括硫解酶）的输入中发挥作用。我们报告了使用解脂耶氏酵母的各种过氧化物进行酵母双杂交分析的结果，并更全面地表征了 Pex8p 和 Pex20p 之间的相互作用。免疫共沉淀表明Pex8p和Pex20p形成复合物，而体外结合研究表明Pex8p和Pex20p之间的相互作用是特异性的、直接的和自主的。 Pex8p 在 PEX20 破坏菌株的细胞中与过氧化物酶体分级，表明 Pex20p 对于 Pex8p 靶向过氧化物酶体不是必需的。在 PEX8 破坏菌株的细胞中，硫解酶主要是胞质的，而 Pex20p 和少量硫解酶与过氧化物酶体结合，表明 Pex8p 参与 Pex20p-硫解酶复合物对接至膜后硫解酶的输入。在没有 Pex8p 的情况下，过氧化物酶体硫解酶和 Pex20p 受到保护，免受外部添加的蛋白酶的作用。这一发现与 Pex8p 位于过氧化物酶体内的事实一起表明，Pex20p 在输入过程中可能伴随硫解酶进入过氧化物酶体。
Peroxins are proteins required for peroxisome assembly. The cytosolic peroxin Pex20p binds directly to the β-oxidation enzyme thiolase and is necessary for its dimerization and peroxisomal targeting. The intraperoxisomal peroxin Pex8p has a role in the import of peroxisomal matrix proteins, including thiolase. We report the results of yeast two-hybrid analyses with various peroxins of the yeast Yarrowia lipolytica and characterize more fully the interaction between Pex8p and Pex20p. Coimmunoprecipitation showed that Pex8p and Pex20p form a complex, while in vitrobinding studies demonstrated that the interaction between Pex8p and Pex20p is specific, direct, and autonomous. Pex8p fractionates with peroxisomes in cells of a PEX20 disruption strain, indicating that Pex20p is not necessary for the targeting of Pex8p to peroxisomes. In cells of a PEX8 disruption strain, thiolase is mostly cytosolic, while Pex20p and a small amount of thiolase associate with peroxisomes, suggesting the involvement of Pex8p in the import of thiolase after docking of the Pex20p-thiolase complex to the membrane. In the absence of Pex8p, peroxisomal thiolase and Pex20p are protected from the action of externally added protease. This finding, together with the fact that Pex8p is intraperoxisomal, suggests that Pex20p may accompany thiolase into peroxisomes during import.
酵母的免疫荧光方法。
影响因子：
--
作者：
Pringle,JR;Adams,AE;Drubin,DG;Haarer,BK
通讯作者：
Haarer,BK