Centre for Plant Sciences, Irene Manton Building, University of Leeds, Leeds LS2 9JT, UK; School of Chemistry, University of Leeds, Leeds LS2 9JT, UK.
School of Chemistry, University of Leeds, Leeds LS2 9JT, UK.
FEBS Lett. 2014 Jun 27;588(14):2223-9. doi: 10.1016/j.febslet.2014.05.038. Epub 2014 May 28.
PEX5 acts as a cycling receptor for import of PTS1 proteins into peroxisomes and as a co-receptor for PEX7, the PTS2 receptor, but the mechanism of cargo unloading has remained obscure. Using recombinant protein domains we show PEX5 binding to the PEX14N-terminal domain (PEX14N) has no effect on the affinity of PEX5 for a PTS1 containing peptide. PEX5 can form a complex containing both recombinant PTS1 cargo and endogenous PEX7-thiolase simultaneously but isolation of the complex via the PEX14 construct resulted in an absence of thiolase, suggesting a possible role for PEX14 in the unloading of PTS2 cargos.
PEX5 作为 PTS1 蛋白进入过氧化物酶体的循环受体，以及 PEX7（PTS2 受体）的共受体发挥作用，但货物卸载的机制仍不清楚。使用重组蛋白结构域，我们发现 PEX5 与 PEX14N-末端结构域（PEX14N）的结合对 PEX5 与含 PTS1 肽的亲和力没有影响。PEX5 可以形成同时包含重组 PTS1 货物和内源性 PEX7-硫解酶的复合物，但通过 PEX14 构建体分离复合物导致硫解酶缺失，这表明 PEX14 可能在 PTS2 货物的卸载中发挥作用。
