Brocard C, Lametschwandtner G, Koudelka R, Hartig A
Institut für Biochemie und Molekulare Zellbiologie der Universität Wien and Ludwig Boltzmann-Forschungsstelle für Biochemie, Vienna Biocenter, Dr. Bohrgasse 9, A-1030 Wien, Austria.
EMBO J. 1997 Sep 15;16(18):5491-500. doi: 10.1093/emboj/16.18.5491.
To identify members of the translocation machinery for peroxisomal proteins, we made use of the two-hybrid system to establish a protein linkage map centered around Pex5p from Saccharomyces cerevisiae, the receptor for the C-terminal peroxisomal targeting signal (PTS1). Among the five interaction partners identified, Pex14p was found to be induced under conditions allowing peroxisome proliferation. Deletion of the corresponding gene resulted in the inability of yeast cells to grow on oleate as well as the absence of peroxisomal structures. The PEX14 gene product of approximately 38 kDa was biochemically and ultrastructurally demonstrated to be a peroxisomal membrane protein, despite the lack of a membrane-spanning domain. This protein was shown to interact with itself, with Pex13p and with both PTS receptors, Pex5p and Pex7p, indicating a central function for the import of peroxisomal matrix proteins, either as a docking protein or as a releasing factor at the organellar membrane.
为了鉴定过氧化物酶体蛋白转运机制的成员,我们利用双杂交系统构建了一个以酿酒酵母的Pex5p为中心的蛋白质连锁图谱,Pex5p是C端过氧化物酶体靶向信号(PTS1)的受体。在鉴定出的五个相互作用伙伴中,发现Pex14p在允许过氧化物酶体增殖的条件下被诱导。相应基因的缺失导致酵母细胞无法在油酸上生长,并且不存在过氧化物酶体结构。尽管缺乏跨膜结构域,但通过生化和超微结构证明,约38 kDa的PEX14基因产物是一种过氧化物酶体膜蛋白。该蛋白被证明可与自身、Pex13p以及两种PTS受体Pex5p和Pex7p相互作用,表明其在过氧化物酶体基质蛋白导入过程中具有核心功能,要么作为对接蛋白,要么作为细胞器膜上的释放因子。