title: Mitofilin and CHCHD6 physically interact with Sam50 to sustain cristae structure.
abstract: The inner mitochondrial membrane (IMM) invaginates to form cristae and the maintenance of cristae depends on the mitochondrial contact site (MICOS) complex. Mitofilin and CHCHD6, which physically interact, are two components of the MICOS. In this study, we performed immunoprecipitation experiments with Mitofilin and CHCHD6 antibodies and identified a complex containing Mitofilin, Sam50, and CHCHD 3 and 6. Using transcription activator-like effector nucleases (TALENs), we generated knockdown/knockout clones of Mitofilin and CHCHD6. Transmission electron microscopy (TEM) revealed that vesicle-like cristae morphology appeared in cell lines lacking Mitofilin, and mitochondria exhibited lower cristae density in CHCHD6-knockout cells. Immunoblot analysis showed that knockdown of Mitofilin, but not knockout of CHCHD6, affected their binding partners that control cristae morphology. We also demonstrated that Mitofilin and CHCHD6 directly interacted with Sam50. Additionally, we observed that Mitofilin-knockdown cells showed decreased mitochondrial membrane potential (ΔΨm) and intracellular ATP content, which were minimally affected in CHCHD6-knockout cells. Taken together, we conclude that the integrity of MICOS and its efficient interaction with Sam50 are indispensable for cristae organization, which is relevant to mitochondrial function.
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.
authors.forename: Chengli
authors.initials: C
authors.lastname: Ding
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.
authors.forename: Zhifei
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Huang
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.|Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China.
authors.forename: Yajie
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xue
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.
authors.forename: Si
authors.initials: S
authors.lastname: Chen
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.
authors.forename: Zixin
authors.initials: Z
authors.lastname: Deng
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.
authors.forename: Lianrong
authors.initials: L
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Zhiyin
authors.initials: Z
authors.lastname: Song
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Medical Research Institute, Wuhan University, Wuhan, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Chen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000906:Antibodies / Q000276:immunology; D045744:Cell Line, Tumor; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000235:genetics*; D008565:Membrane Proteins / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D051336:Mitochondrial Membranes / Q000502:physiology*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D000906:Antibodies; C521110:CHCHD3 protein, human; C522814:CHCHD6 protein, human; C088548:IMMT protein, human; D008565:Membrane Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D046912:Multiprotein Complexes; D009124:Muscle Proteins; C522815:SAMM50 protein, human; D000255:Adenosine Triphosphate