Harbour Michael E, Seaman Matthew N J
University of Cambridge; Cambridge Institue for Medical Research; Addenbrookes Hospital; Cambridge, UK.
Commun Integr Biol. 2011 Sep;4(5):619-22. doi: 10.4161/cib.16855. Epub 2011 Sep 1.
The retromer complex is conserved across all eukaryotic species and functions in physiologically important sorting processes at the endosomal membrane. A key component of retromer is the VPS29 protein that, although structurally similar to phospho-diesterases, has been convincingly shown in the recent study by Swarbrick et al. (PLoS One 6:e20420, 2011) to be a rigid scaffold that interacts with various proteins that function with retromer in endosomal protein sorting. A widely held view, based on initial observations in Saccharomyces cerevisiae, is that retromer functions as a stable heteropentamer. This is, however, contrary to experimental data presented in Swarbrick et al. (and in other studies) that indicate that retromer in higher eukaryotes is a looser association of two subcomplexes that respectively mediate cargo-selection and membrane tubulation. Here we present an analysis of evolutionary variation of the VPS29 protein and discuss why the retromer complex as first characterized in S. cerevisiae is not representative of retromer in other eukaryotic taxa.
回收体复合物在所有真核生物物种中都保守存在，并在内体膜上具有重要生理功能的分选过程中发挥作用。回收体的一个关键组分是VPS29蛋白，尽管其结构与磷酸二酯酶相似，但Swarbrick等人（《公共科学图书馆·综合》6：e20420，2011）最近的研究令人信服地表明，它是一种刚性支架，可与在内体蛋白分选中与回收体共同发挥作用的各种蛋白质相互作用。基于在酿酒酵母中的初步观察，一种广泛持有的观点是回收体作为一种稳定的异五聚体发挥作用。然而，这与Swarbrick等人（以及其他研究）提出的实验数据相反，这些数据表明高等真核生物中的回收体是两个亚复合物的较松散结合，分别介导货物选择和膜微管形成。在此，我们对VPS29蛋白的进化变异进行了分析，并讨论了为何最初在酿酒酵母中表征的回收体复合物不能代表其他真核生物类群中的回收体。
