Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, Sweden.
Max-Planck-Institut für Biologie des Alterns, Gleueler Str. 50a, D-50931 Cologne, Germany.
Biochem Biophys Res Commun. 2014 Jan 3;443(1):7-12. doi: 10.1016/j.bbrc.2013.10.137. Epub 2013 Nov 6.
UBTD1 is a previously uncharacterized ubiquitin-like (UbL) domain containing protein with high homology to the mitochondrial Dc-UbP/UBTD2 protein. Here we show that UBTD1 and UBTD2 belong to a family of proteins that is conserved through evolution and found in metazoa, funghi, and plants. To gain further insight into the function of UBTD1, we screened for interacting proteins. In a yeast-2-hybrid (Y2H) screen, we identified several proteins involved in the ubiquitylation pathway, including the UBE2D family of E2 ubiquitin conjugating enzymes. An affinity capture screen for UBTD1 interacting proteins in whole cell extracts also identified members of the UBE2D family. Biochemical characterization of recombinant UBTD1 and UBE2D demonstrated that the two proteins form a stable, stoichiometric complex that can be purified to near homogeneity. We discuss the implications of these findings in light of the ubiquitin proteasome system (UPS).
UBTD1 是一种以前未被描述的泛素样 (UbL) 结构域蛋白，与线粒体 Dc-UbP/UBTD2 蛋白具有高度同源性。在这里，我们表明 UBTD1 和 UBTD2 属于一个在进化过程中保守的蛋白质家族，存在于原生动物、真菌和植物中。为了更深入地了解 UBTD1 的功能，我们筛选了相互作用的蛋白质。在酵母双杂交 (Y2H) 筛选中，我们鉴定出了几种参与泛素化途径的蛋白质，包括 UBE2D 家族的 E2 泛素连接酶。在全细胞提取物中的 UBTD1 相互作用蛋白的亲和捕获筛选中，也鉴定出了 UBE2D 家族的成员。重组 UBTD1 和 UBE2D 的生化特性表明，这两种蛋白质形成了稳定的、化学计量比的复合物，可以近乎纯的状态进行纯化。我们根据泛素蛋白酶体系统 (UPS) 讨论了这些发现的意义。
