Mitochondrial transcripts are subject to a wealth of processing mechanisms including cis- and trans-splicing events, as well as base modifications (RNA editing). Hundreds of proteins are required for these processes in plant mitochondria, many of which belong to the pentatricopeptide repeat (PPR) protein superfamily. The structure, localization, and function of these proteins is only poorly understood. Here we present evidence that several PPR proteins are bound to mitoribosomes in plants. A nov ...[more]
Project description:Recent genomic studies revealed that mitochondria from mistletoe species appear to lack a major amount of genes, indicating a possible loss of the NADH ubiquinone oxidoreductase (complex I) which forms an essential part of the mitochondrial Oxidative Phosphorylation System (OXPHOS). This dataset is used for profiling of the mitochondrial complexome from European mistletoe, Viscum album and gives biochemical evidence for a lack of complex I as well as a unique composition of OXPHOS in Viscum album.
Project description:NDUFC2 is a subunit of the membrane part of NADH:ubiquinone oxidoreductase (complex I). Here we used complexome profiling to study the role of NDUFC2 in complex I stability and assembly.
Project description:NDUFAF8 is an assembly factor of the NADH:ubiquinone oxidoreductase (complex I). Here we used complexome profiling the functional consequences of NDUFAF8 mutations in patient fibroblasts.
Project description:Here we analysed the impact of two subunits of the mitochondrial contact site and cristae organizing system (MICOS) complex, MIC26 and MIC27, on the assembly and stability of mitochondrial complexes of the oxidative phosphorylation system (OXPHOS).
Project description:Mitochondrial respiratory chain (MRC) complexes I, III and IV are associated into large molecular structures named supercomplexes (SCs) or respirasomes, whose functional roles remain to be fully understood. Biochemical analyses in a diversity of OXPHOS-deficient cellular and animal models support the idea that one of the SCs function is to confer stability to individual MRC complexes, in particular to complex I (CI). To gain insight into the mechanisms that regulate the structural interdependences among MRC complexes, we performed complexome profiling of human cybrids laking mitochondrial genes Cox1 or Cox2 and compared protein assemblies and intermediates to control 143B cells.
Project description:The nosocomial pathogen Acinetobacter baumannii is a frequent cause of hospital acquired infections worldwide, and a challenge for treatment due to its evolved resistance to antibiotics, including carbapenems. To gain insight on A. baumannii antibiotic resistance mechanisms, we analyzed the protein interaction network of a multidrug-resistant A. baumannii clinical strain Ab5075. Using in vivo chemical cross-linking and mass spectrometry, we identified 2,068 non-redundant cross-linked peptide pairs containing 245 intra- and 398 inter- molecular interactions. Outer membrane proteins OmpA and YiaD, and carbapenemase Oxa-23 are hubs of the identified interaction network. Eighteen novel interactors of Oxa-23 were identified. Interactions of Oxa-23 with outer membrane porins OmpA and CarO were verified with co-immunoprecipitation analysis. Furthermore, transposon mutagenesis of oxa-23 or interactors of Oxa-23 demonstrated changes in meropenem or imipenem sensitivity in Ab5075. These results provide the first view of a porin-localized toxin inactivation model and increase understanding of bacterial antibiotic resistance mechanisms.
Project description:We performed ChIP-seq in the GR18 cell line (derived from U2OS ATTC:HTB-96, stably transfected with an expression construct for GR), upon glucocorticoid (dexamethasone)treatment for 90 minutes. Cells were cross-linked with 1% formaldehyde for 3 minutes.