Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China.
State Key Laboratory of Trauma and Chemical Poisoning, Army Medical University (Third Military Medical University), Chongqing, China.
Autophagy. 2024 Dec;20(12):2830-2832. doi: 10.1080/15548627.2024.2403125. Epub 2024 Sep 18.
() is a facultative intracellular parasitic pathogen with multiple immune escape mechanisms. Mitophagy is critical for mitochondrial quality control and function in various biological processes. We reported that infection induces mitophagy to promote its intracellular survival by decreasing mitochondrial reactive oxygen species (mtROS). Mechanically, infection leads to the rupture of host outer mitochondrial membrane (OMM) by DNM1L/DRP1 (dynamin 1-like). Furthermore, BipD, the type III secretion system (T3SS) needle tip protein of , hijacks the host KLHL9 (kelch-like 9)-KLHL13 (kelch-like 13)-CUL3 (cullin 3) E3 ubiquitin ligase complex to promote the K63-linked ubiquitination of IMMT/mitofilin (inner membrane protein, mitochondrial) at the K211 site. Then BipD-initiated mitophagy, via the conventional macroautophagy/autophagy pathway with the receptor SQSTM1 (sequestosome 1) involvement, decreases the mtROS production, which in turn facilitates the intracellular survival of . Here, our findings reveal an unexpected function of BipD and the KLHL9-KLHL13-CUL3 E3 ligase complex and suggest a novel mechanism used by bacterial pathogens that hijack host mitophagy for their survival.
() 是一种兼性细胞内寄生病原体,具有多种免疫逃避机制。线粒体自噬对于线粒体的质量控制和各种生物过程的功能至关重要。我们报道, 感染通过减少线粒体活性氧物质 (mtROS) 诱导线粒体自噬,以促进其细胞内存活。从机制上讲, 感染通过 DNM1L/DRP1(肌球蛋白 1 样)导致宿主外线粒体膜 (OMM) 的破裂。此外, 型分泌系统 (T3SS) 针状蛋白 BipD 劫持宿主 KLHL9(kelch 样 9)-KLHL13(kelch 样 13)-CUL3(cullin 3)E3 泛素连接酶复合物,促进 IMMT/mitofilin(内膜蛋白,线粒体)在 K211 位的 K63 连接泛素化。然后,BipD 引发的线粒体自噬通过涉及受体 SQSTM1(自噬相关蛋白 1)的常规巨自噬/自噬途径,减少 mtROS 的产生,从而促进 的细胞内存活。在这里,我们的发现揭示了 BipD 和 KLHL9-KLHL13-CUL3 E3 连接酶复合物的意外功能,并提出了一种新的机制,即细菌病原体利用宿主的线粒体自噬来生存。