Gouveia A M, Reguenga C, Oliveira M E, Sa-Miranda C, Azevedo J E
Instituto de Biologia Molecular e Celular and Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4150-180 Porto, Portugal.
J Biol Chem. 2000 Oct 20;275(42):32444-51. doi: 10.1074/jbc.M004366200.
Pex5p is the receptor for the vast majority of peroxisomal matrix proteins. Here, we show that about 15% of rat liver Pex5p is found in the peroxisomal fraction representing 0.06% of total peroxisomal protein. This population of Pex5p displays all the characteristics of an intrinsic membrane protein. Protease protection assays indicate that this pool of Pex5p has domains exposed on both sides of the peroxisomal membrane. The strong interaction of Pex5p with the membrane of the organelle is not affected by mild protease treatment of intact organelles, conditions that result in the partial degradation of Pex13p. Cytosolic Pex5p is a monomeric protein. In contrast, virtually all peroxisomal Pex5p was found to be part of a stable 250-kDa protein assembly. This complex was isolated and shown to comprise just two subunits, Pex5p and Pex14p.
Pex5p是绝大多数过氧化物酶体基质蛋白的受体。在此，我们发现大鼠肝脏中约15%的Pex5p存在于过氧化物酶体组分中，占过氧化物酶体总蛋白的0.06%。这部分Pex5p表现出内在膜蛋白的所有特征。蛋白酶保护试验表明，这部分Pex5p在过氧化物酶体膜两侧都有结构域暴露。Pex5p与细胞器膜的强烈相互作用不受对完整细胞器进行温和蛋白酶处理的影响，这种处理会导致Pex13p部分降解。胞质中的Pex5p是一种单体蛋白。相比之下，几乎所有过氧化物酶体中的Pex5p都被发现是一个稳定的250 kDa蛋白质组装体的一部分。该复合物被分离出来，显示仅由两个亚基组成，即Pex5p和Pex14p。
