Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Molecular characterization of a complex of Apoptosis Inducing Factor 1 (AIFM1) with cytochrome c oxidase of the mitochondrial respiratory chain

ABSTRACT: Combining mass spectrometry based chemical cross-linking and complexome profiling, we analyzed the interactome of heart mitochondria. We focused on complexes of oxidative phosphorylation and found that dimeric apoptosis inducing factor 1 (AIFM1) forms a defined complex with ~10% of monomeric cytochrome c oxidase (COX), but hardly interacts with respiratory chain supercomplexes. Multiple AIFM1 inter-crosslinks engaging six different COX subunits provided structural restraints to build a detailed atomic model of the COX-AIFM12 complex. Application of two complementary proteomic approaches thus provided unexpected insight into the macromolecular organization of the mitochondrial complexome. Our structural model excludes direct electron transfer between AIFM1 and COX. Notably however, the binding site of cytochrome c remains accessible allowing formation of a ternary complex. The discovery of the previously overlooked COX-AIFM12 complex and clues provided by the structural model hint at a role of AIFM1 in OXPHOS biogenesis and in programmed cell death.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Bos Taurus (bovine)

TISSUE(S): Heart

SUBMITTER: Johannes Hevler

LAB HEAD: Albert J.R. Heck

PROVIDER: PXD025102 | Pride | 2021-09-09

REPOSITORIES: Pride

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
	20190913_L1_Ag1_hevle001_SA_Bovine_Mito_XL_DSSO_fr10.raw	Raw
	20190913_L1_Ag1_hevle001_SA_Bovine_Mito_XL_DSSO_fr11.raw	Raw
	20190913_L1_Ag1_hevle001_SA_Bovine_Mito_XL_DSSO_fr12.raw	Raw
	20190913_L1_Ag1_hevle001_SA_Bovine_Mito_XL_DSSO_fr13.raw	Raw
	20190913_L1_Ag1_hevle001_SA_Bovine_Mito_XL_DSSO_fr14.raw	Raw

Items per page:

1 - 5 of 161

Similar Datasets

MRPS36 provides a missing link in the eukaryotic 2-oxoglutarate dehydrogenase complex for recruitment of E3 to the E2 core - Phospoproteomics data

Project description:The tricarboxylic acid (TCA) cycle, or Krebs cycle, is the central pathway of energy production in eukaryotic cells and plays a key part in aerobic respiration throughout all kingdoms of life. The enzymes involved in this cycle generate the reducing equivalents NADH and FADH2 by a series of enzymatic reactions, which are utilized by the electron transport chain to produce ATP. One of the key enzymes in this cycle is 2-oxoglutarate dehydrogenase (OGDHC), which generates NADH by oxidative decarboxylation of 2-oxoglutarate to succinyl-CoA. Notably, this enzyme consists of multiple subunits as a megadalton protein complex. Thus far, it was thought that OGDHC consists of solely three catalytically active subunits (E1, E2, E3). However in fungi and animals, the small protein MRPS36 has been proposed as a putative additional component. Based on extensive XL-MS data obtained from measurements in both, mice and bovine heart mitochondria, and from phylogenetic analyses, we provide structural evidence that MRPS36 is an exclusive and crucial member of eukaryotic OGDHC. Comparative genomics analysis and computational structure predictions reveal that in eukaryotic OGDHC, E2o does not contain a peripheral subunit-binding (PSBD) domain. Instead, our data provide compelling evidence that in eukaryotes, MRPS36 evolved as E3 adaptor protein, functionally replacing the PSBD domain. Based on our data we provide a refined structural model of the complete eukaryotic OGDHC assembly containing all its 58 subunits (~ 3.4 MDa). The model provides new insights into the protein-protein interactions within the OGDH complex and highlights putative mechanistic implications.

2023-03-10 | PXD036896 | Pride

Cullin-RING ligases target substrates with geometrically optimized catalytic partners

Project description:Cullin-RING ubiquitin ligases (CRLs) control the degradation of a wide landscape of human proteins in combination with ubiquitin-carrying enzymes (UCEs). CRL expansion during evolution is apparent, with a few dozen in yeast that function with a single UCE and as many as 300 in humans that function with at least 8 UCEs. A major unaddressed question is why human CRL buildup has been accompanied by additional UCEs that function with CRLs. Here we demonstrate that human CRLs and UCEs can display specificity, resulting in increased affinity for each other and enhanced rates of ubiquitin transfer to substrates. To uncover the structural basis for CRL-UCE specificity, cryo-EM was performed on a CRL2 subfamily member with substrate receptor subunit FEM1C (CRL2FEM1C) in complex with a proxy for catalytically active UCE. The structure elucidated an extensive CRL-UCE interface that promotes proximity between the UCE active site and CRL2FEM1C-bound substrate. Unanticipated selectivity was also observed between the CRL substrate Lys ubiquitylation sites and the identity of the UCE. CRL-UCE specificity also manifests during targeted protein degradation by affecting the activities of drugs that induce ubiquitylation of neosubstrates. An emerging CRL code is revealed that drives selective formation of CRL-UCE complexes to promote rapid substrate ubiquitylation.

2024-05-22 | PXD043523 | Pride

Notch-Jagged signaling complex defined by an interaction mosaic

Project description:The Notch signaling system links cellular fate to that of its neighbors, driving proliferation, apoptosis, and cell differentiation in metazoan organisms, whereas dysfunction leads to debilitating developmental disorders and cancers. Here we probe the molecular architecture of mammalian Notch1 full ectodomain in complex with the canonical ligand Jagged1 using cross-linking mass spectrometry (XL-MS). Our data reveals that three Jagged1 sites, C2-epidermal growth factor (EGF) 1, EGF10 and cysteine-rich domain (CRD), are in proximity to the Notch1 negative regulatory region (NRR) in the Notch1-Jagged1 full ectodomain complex. We verified direct interactions and identified additional interacting regions by quantitative-binding experiments. In addition, XL-MS and structural analysis reveal Notch1 and Jagged1 ectodomain intramolecular interactions and structural flexibility that support the formation of backfolded architectures. Together the data suggest a direct and intricate role for the different extracellular regions of Notch1 and Jagged1 in the activation and regulation of Notch1 signaling.

2021-07-08 | PXD023072 | Pride

Normal respiratory chain capacity and physiology in mice with severely reduced levels of mitochondrial respirasomes; Cross-linking of intact mitochondria

Project description:The mammalian oxidative phosphorylation (OXPHOS) system in the inner mitochondrial membrane comprises respiratory chain complexes I-IV (CI-CIV) and ATP synthase. Together, these protein complexes harvest metabolic energy to generate ATP, the cellular energy currency. The inner mitochondrial membrane is abundant in OXPHOS complexes and CI, CIII and CIV exhibit specific protein-protein interactions to form stable supercomplex assemblies, exemplified by the respirasome (CI-CIII2-CIV). Respirasomes are conserved in evolution, and as well documented by biochemical and structural methods. However, their physiological roles are much debated, despite a substantial literature suggesting their importance in facilitating catalysis and regulating turnover in response to metabolic demand. To investigate the in vivo role of respirasomes, we deleted a short conserved, charged loop in the UQCRC1 subunit of CIII that contacts CI. The resulting homozygous knock-in mice show profoundly decreased levels of respirasomes on blue native polyacrylamide gel electrophoresis (BN-PAGE) and complexome profiling proteomics analyses of different tissues, although the individual complexes appear unaffected. In vivo The spatial organization of respirasomes in vivo was altered in knock-in mice as shown by cross-linking experiments on intact mitochondria. Surprisingly, the mutant mice are healthy, with normal respiratory chain capacity and normal exercise tolerance. Therefore, respirasomes are dispensable for OXPHOS function in vivo.

2023-03-11 | PXD031345 | Pride

Structural basis for the assembly of Mis18a/b core modules

Project description:The centromere, defined by the enrichment of CENP-A (a Histone H3 variant) containing nucleosomes, is a specialised chromosomal locus that acts as a microtubule attachment site. To preserve centromere identity, CENP-A levels must be maintained through active CENP-A loading during the cell cycle. A central player mediating this process is the Mis18 complex (Mis18a, Mis18b and Mis18BP1), which recruits the CENP-A specific chaperone HJURP to centromeres for CENP-A deposition. Here, using a multi-pronged approach, we characterise the structure of the Mis18 complex and show that multiple hetero- and homo-oligomeric interfaces facilitate the hetero-octameric Mis18 complex assembly composed of 4 Mis18a, 2 Mis18b and 2 Mis18BP1. Evaluation of structure-guided/separation-of-function mutants reveals structural determinants essential for Mis18 complex assembly and centromere maintenance. Our results provide new mechanistic insights on centromere maintenance, highlighting that while Mis18a can associate with centromeres and deposit CENP-A independently of Mis18b, the latter is indispensable for the optimal level of CENP-A loading required for preserving the centromere identity.

2024-09-25 | PXD052964 | Pride

Integrative Structural Characterization of the Human Canonical and Non-canonical Cop9 Signalosome Complexes

Project description:The COP9 signalosome (CSN) is an evolutionarily conserved protein complex that functions as a deneddylase to inactivate Cullin-RING E3 ligases for controlling protein ubiquitination. CSN possesses structural flexibility that is important for its activation upon binding to a diverse array of CRLs. The canonical and non-canonical CSN complexes consist of 8 (CSN1-8) and 9 (CSN1-9) subunits, respectively. Although CSN9 is not essential for CSN assembly and function, it appears to be important in non-catalytic regulation of CRLs by CSN. Here we employed a combinatory cross-linking mass spectrometry (XL-MS) approach to generate the largest PPI maps of human CSN complexes, which significantly enhanced the precision of integrative structural modeling. The resulting integrative structures allowed us not only to elucidate architectures of both complexes, but also to assess CSN structural dynamics that was not described in the crystal structure. In addition, we have determined CSN9 docking sites and its impact on the CSN structure. While CSN9 binding did not induce global conformational changes, it triggered subunit local reorientations that may be associated with CSN9 involvement in CSN-mediated steric regulation of CRLs.

2020-02-04 | PXD014673 | Pride

Comparison of OpenPepXL and xQuest on a Labeled Cross-Linking MS dataset

Project description:These data sets are part of a large study aimed at the comparison of experimental and computational workflows used in chemical cross-linking coupled to mass spectrometry. Bovine serum albumin (BSA) was used as a model protein. Two different cross-linking chemistries were used: disuccinimidyl suberate (DSS) and a combination of pimelic acid dihydrazide (PDH) and the coupling reagent, DMTMM. See related publication: Iacobucci et al., First Community-Wide, Comparative Cross-Linking Mass Spectrometry Study, Analytical Chemistry, 91 (2019) 6953-6961, DOI: 10.1021/acs.analchem.9b00658 This project is a reanalysis of these datasets with the two Labeled Cross-Linking MS identification tools OpenPepXL and xQuest.

2020-10-20 | PXD014523 | Pride

Cross-linking mass spectrometry uncovers interactions between high-density lipoproteins and the SARS-CoV-2 spike glycoprotein

Project description:Multiple studies to date have shown that high-density lipoprotein (HDL) levels are reduced in patients with coronavirus disease 2019 (COVID-19), and that the extent of this reduction is associated with poor clinical outcomes. While lipoproteins are known to play a key role during the lifecycle of hepatitis C virus, the direct influence they have upon coronavirus (CoV) infections remains poorly understood. In this study we utilise cross-linking mass spectrometry (XL-MS) to determine circulating protein interactors of the severe acute respiratory syndrome (SARS)-CoV-2 spike glycoprotein. Spike was revealed to interact with HDL, through direct interactions with apolipoprotein (Apo)-A1, ApoC3 and ApoD, highlighting multiple modalities of how SARS-CoV-2 and HDL may interact. XL-MS of plasma isolated from COVID-19 patients uncovered HDL protein interaction networks, dominated by acute phase serum amyloid proteins (SAA), whereby serum amyloid A2 (SAA2) was shown to bind to ApoD. ApoD was confirmed to also interact with core apolipoproteins of both LDL and VLDL, suggesting that SARS-CoV-2 may bind multiple lipoprotein species. The interaction between ApoD and spike was further validated in cells using immunoprecipitation-MS, which uncovered a novel interaction between both ApoD and spike with membrane-associated progesterone receptor component 1 (PGRMC1). Mechanistically, XL-MS coupled with data-driven structural modelling determined that ApoD may interact within the receptor-binding domain (RBD) of spike, posing the hypothesis that ApoD may interfere with binding to the angiotensin-converting enzyme 2 (ACE2) receptor. However, utilising multiple cell-based assays we determined ApoD to have no effect upon viral replication or infectivity.

2023-07-20 | PXD041438 | Pride

Cross-linking mass spectrometry uncovers interactions between high-density lipoproteins and the SARS-CoV-2 spike glycoprotein

2023-07-20 | PXD041831 | Pride

Cross-linking mass spectrometry uncovers interactions between high-density lipoproteins and the SARS-CoV-2 spike glycoprotein

2023-07-20 | PXD036640 | Pride