Department of Biology, Eidgenössische Technische Hochschule Zurich, Institute of Molecular Biology and Biophysics, Schafmattstrasse 20, Zurich CH-8093, Switzerland.
EMBO Rep. 2010 Oct;11(10):791-7. doi: 10.1038/embor.2010.119. Epub 2010 Aug 27.
Post-translational modification of proteins with prokaryotic ubiquitin-like protein (Pup) is the bacterial equivalent of ubiquitination in eukaryotes. Mycobacterial pupylation is a two-step process in which the carboxy-terminal glutamine of Pup is first deamidated by Dop (deamidase of Pup) before ligation of the generated γ-carboxylate to substrate lysines by the Pup ligase PafA. In this study, we identify a new feature of the pupylation system by demonstrating that Dop also acts as a depupylase in the Pup proteasome system in vivo and in vitro. Dop removes Pup from substrates by specific cleavage of the isopeptide bond. Depupylation can be enhanced by the unfolding activity of the mycobacterial proteasomal ATPase Mpa.
蛋白质的翻译后修饰与原核泛素样蛋白（Pup）是细菌中与真核生物中泛素化作用相当的过程。分枝杆菌的 Pup 化作用是一个两步过程，其中 Pup 的羧基末端谷氨酰胺首先被 Dop（Pup 的脱氨酶）脱酰胺化，然后由 Pup 连接酶 PafA 将生成的γ-羧基连接到底物赖氨酸上。在这项研究中，我们通过证明 Dop 在体内和体外的 Pup 蛋白酶体系统中也作为脱 Pup 酶来鉴定 Pup 化系统的一个新特征。Dop 通过特异性切割异肽键从底物中去除 Pup。脱 Pup 作用可以通过分枝杆菌蛋白酶体 ATP 酶 Mpa 的展开活性增强。
