Fischer Annette, Harrison Kelly S, Ramirez Yesid, Auer Daniela, Chowdhury Suvagata Roy, Prusty Bhupesh K, Sauer Florian, Dimond Zoe, Kisker Caroline, Hefty P Scott, Rudel Thomas
Department of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany.
Department of Molecular Biosciences, University of Kansas, lawrence, United States.
Elife. 2017 Mar 28;6:e21465. doi: 10.7554/eLife.21465.
Obligate intracellular replicate in a membrane-bound vacuole called inclusion, which serves as a signaling interface with the host cell. Here, we show that the chlamydial deubiquitinating enzyme (Cdu) 1 localizes in the inclusion membrane and faces the cytosol with the active deubiquitinating enzyme domain. The structure of this domain revealed high similarity to mammalian deubiquitinases with a unique α-helix close to the substrate-binding pocket. We identified the apoptosis regulator Mcl-1 as a target that interacts with Cdu1 and is stabilized by deubiquitination at the chlamydial inclusion. A chlamydial transposon insertion mutant in the Cdu1-encoding gene exhibited increased Mcl-1 and inclusion ubiquitination and reduced Mcl-1 stabilization. Additionally, inactivation of Cdu1 led to increased sensitivity of for IFNγ and impaired infection in mice. Thus, the chlamydial inclusion serves as an enriched site for a deubiquitinating activity exerting a function in selective stabilization of host proteins and protection from host defense.
专性细胞内菌在称为包涵体的膜结合液泡中复制，该液泡作为与宿主细胞的信号传导界面。在此，我们表明衣原体去泛素化酶（Cdu）1定位于包涵体膜上，且活性去泛素化酶结构域面向胞质溶胶。该结构域的结构显示出与哺乳动物去泛素化酶高度相似，在靠近底物结合口袋处有一个独特的α螺旋。我们确定凋亡调节因子Mcl-1是与Cdu1相互作用的靶点，并且在衣原体包涵体处通过去泛素化而稳定。编码Cdu1的基因中的衣原体转座子插入突变体表现出Mcl-1和包涵体泛素化增加以及Mcl-1稳定性降低。此外，Cdu1的失活导致对IFNγ的敏感性增加以及小鼠感染受损。因此，衣原体包涵体是去泛素化活性的富集位点，在宿主蛋白的选择性稳定和免受宿主防御方面发挥作用。
