Similar Datasets
Project description:dAKAP1 signaling complexes coordinate local synthesis at the mitochondrial surface
| PRJNA575262 | ENA
Project description:Compartmentalization of macromolecules is a ubiquitous molecular mechanism that drives numerous cellular functions. The appropriate organization of enzymes in space and time enables the precise transmission and integration of intracellular signals. Molecular scaffolds constrain signaling enzymes to influence the regional modulation of these physiological processes. Mitochondrial targeting of protein kinases and protein phosphatases provides a means to locally control the phosphorylation status and action of proteins on the surface of this organelle. Dual-specificity protein kinase A anchoring protein 1 (dAKAP1) is a multivalent binding protein that targets protein kinase A (PKA), RNAs, and other signaling enzymes to the outer mitochondrial membrane. Many AKAPs recruit a diverse set of binding partners that coordinate a broad range of cellular processes. Here, results of MS and biochemical analyses reveal that dAKAP1 anchors additional components, including the ribonucleoprotein granule components La-related protein 4 (LARP4) and polyadenylate-binding protein 1 (PABPC1). Local translation of mRNAs at organelles is a means to spatially control the synthesis of proteins. RNA-Seq data demonstrate that dAKAP1 binds mRNAs encoding proteins required for mitochondrial metabolism, including succinate dehydrogenase. Functional studies suggest that the loss of dAKAP1-RNA interactions reduces mitochondrial electron transport chain activity. Hence, dAKAP1 plays a previously unappreciated role as a molecular interface between second messenger signaling and local protein synthesis machinery.
| S-EPMC7397098 | biostudies-literature
Project description:Bombyx Papi contains two K-homology (KH) domains and one Tudor domain, and acts as a scaffold for Siwi-piRISC biogenesis on the mitochondrial surface. To initiate this process, Papi binds first to Siwi via the Tudor domain and subsequently to piRNA precursors loaded onto Siwi via the KH domains. This second action depends on phosphorylation of Papi. However, its underlying mechanism remains unknown. Here, we show that Siwi targets Par-1 kinase to mitochondrial Papi to promote its phosphorylation at Ser547 in the auxiliary domain and that this modification enhances the ability of Papi to bind Siwi-bound piRNA precursors via the KH domains. Papi S547A mutant still bound to Siwi, like wild-type (WT) Papi, although it evaded phosphorylation by Par-1: Consequently, Papi lost the ability to bind RNAs, abrogating the generation of Siwi-piRISC. Papi mutant lacking the Tudor and auxiliary domains escaped coordinated regulation by Siwi and Par-1 and lost their bias to bind piRNA precursors. Pseudo-phosphorylation mutants of Papi restored Siwi-piRISC formation in Papi-lacking cells, but their ability to bind RNAs required Siwi, similar to WT Papi. Par-1-dependent, multilayered mechanism by which Siwi regulates the role of Papi in Siwi-piRISC biogenesis was revealed.
2022-01-25 | GSE179432 | GEO
Project description:Mitochondrial fatty acid synthesis coordinates mitochondrial oxidative metabolism
| PRJNA625208 | ENA
Project description:Here we show that TRAP1 directly binds translation elongation factors, both inside and outside mitochondria, and slows down translation. TRAP1 overexpression or silencing affects the synthesis of respiratory complex components. Inside mitochondria, TRAP1 binds the Complex III core component UQCRC2 and regulates Complex III activity. This decreases respiration rate upon basal condition but allows sustained oxidative phosphorylation when glucose is limiting, a condition in which TRAP1-UQCRC2 binding is lost. In humans, TRAP1 is co-expressed with the mitochondrial translational machinery, which synthesize respiratory complex proteins. Altogether, our results show an unprecedented level of complexity in the regulation of cancer cell metabolism, in which mitochondrial and cytosolic protein synthesis are co-regulated with energetic metabolism through the contribution of a common molecular chaperone
2023-12-07 | GSE141616 | GEO
Project description:<p> Human disorders of mitochondrial oxidative phosphorylation (OXPHOS) represent a devastating collection of inherited diseases. These disorders impact at least 1:5000 live births, and are characterized by multi-organ system involvement. They are characterized by remarkable locus heterogeneity, with mutations in the mtDNA as well as in over 77 nuclear genes identified to date. It is estimated that additional genes may be mutated in these disorders. </p> <p>To discover the genetic causes of mitochondrial OXPHOS diseases, we performed targeted, deep sequencing of the entire mitochondrial genome (mtDNA) and the coding exons of over 1000 nuclear genes encoding the mitochondrial proteome. We applied this 'MitoExome' sequencing to 124 unrelated patients with a wide range of OXPHOS disease presentations from the Massachusetts General Hospital Mitochondrial Disorders Clinic. </p> <p>The 2.3Mb targeted region was captured by hybrid selection and Illumina sequenced with paired 76bp reads. The total set of 1605 targeted nuclear genes included 1013 genes with strong evidence of mitochondrial localization from the MitoCarta database, 377 genes with weaker evidence of mitochondrial localization from the MitoP2 database and other sources, and 215 genes known to cause other inborn errors of metabolism. Approximately 88% of targeted bases were well-covered (>20X), with mean 200X coverage per targeted base. </p>
| phs000339 | dbGaP
Project description:Mitochondria house anabolic and catabolic processes that must be balanced and rapidly adjusted to meet the cellular demands. CLUH binds mRNAs of nuclear encoded mitochondrial proteins and is highly expressed in the liver, where it regulates metabolic plasticity by an ill-defined mechanism. Here, we show that CLUH-dependent regulation of mitochondrial function is spatially organized through the coalescence of CLUH and its target mRNAs in specific G3BP1-positive granules. These CLUH-dependent granules protect mRNAs involved in mitochondrial energy-converting pathways from decay and define their translational fate to match nutrient availability. CLUH granules suppress premature mTORC1 activation during nutrient deprivation, inhibiting mitochondrial anabolic pathways. Lack of spatial CLUH regulation causes mTORC1 hyperactivation, which impairs mitophagy and triggers cell death. Our data demonstrate that the temporal catabolic adaptation of mitochondria depends on a compartmentalized CLUH-dependent post-transcriptional mechanism that controls mTORC1 signaling and mitochondrial turnover, thus ensuring survival.
2020-03-19 | PXD014098 | Pride
Project description:Protein homeostasis in eukaryotic organelles and their progenitor prokaryotes is regulated by a series of ATP-dependent proteases including the caseinolytic protease complex (ClpXP). In chloroplasts, ClpXP has essential roles in organelle biogenesis and maintenance , but the significance of the plant mitochondrial ClpXP remains unknown and factors that aid coordination of nuclear and mitochondrial encoded subunits for complex assembly in mitochondria await discovery. In this study, we generated knock-out lines of the single copy mitochondrial Clp protease subunit, CLPP2, in Arabidopsis thaliana. They have higher abundance of transcripts from mitochondrial genes encoding OXPHOS protein complexes, while transcripts for nuclear genes encoding other subunits of the same complexes showed no change in transcript abundance. In contrast, the protein abundance of specific nuclear-encoded subunits in OXPHOS complexes I and V increased in knockouts, without accumulation of mitochondrial-encoded counterparts in the same complex. Protein complexes mainly or wholly encoded in the nucleus were unaffected. Analysis of protein import, assembly and function of Complex I revealed that while function was retained, protein homeostasis was disrupted through slower assembly, leading to accumulation of soluble subcomplexes of nuclear-encoded subunits after import. It is proposed that CLPP contributes to the mitochondrial protein degradation network through supporting coordination and assembly of protein complexes encoded across mitochondrial and nuclear genomes.
2019-12-13 | GSE141942 | GEO
Project description:A new family of low-coordinate nickel imides supported by 1,2-bis(di-tert-butylphosphino)ethane was synthesized. Oxidation of nickel(II) complexes led to the formation of both aryl- and alkyl-substituted nickel(III)-imides, and examples of both types have been isolated and fully characterized. The aryl substituent that proved most useful in stabilizing the Ni(III)-imide moiety was the bulky 2,6-dimesitylphenyl. The two Ni(III)-imide compounds showed different variable-temperature magnetic properties but analogous EPR spectra at low temperatures. To account for this discrepancy, a low-spin/high-spin equilibrium was proposed to take place for the alkyl-substituted Ni(III)-imide complex. This proposal was supported by DFT calculations. DFT calculations also indicated that the unpaired electron is mostly localized on the imide nitrogen for the Ni(III) complexes. The results of reactions carried out in the presence of hydrogen donors supported the findings from DFT calculations that the adamantyl substituent was a significantly more reactive hydrogen-atom abstractor. Interestingly, the steric properties of the 2,6-dimesitylphenyl substituent are important not only in protecting the Ni═N core but also in favoring one rotamer of the resulting Ni(III)-imide, by locking the phenyl ring in a perpendicular orientation with respect to the NiPP plane.
| S-EPMC3192028 | biostudies-literature
Project description:The DNA in mitochondria is associated with the inner of two membranes and it co-fractionates with the limited amount of cholesterol in the organelles. However, the effects of mitochondrial cholesterol deficiency are largely unknown, and mitochondrial disorders relating to this area of cell metabolism have not been reported hitherto. Using detailed SNP array analysis we have identified patients with impaired cerebellar development and neurological dysfunction who have large deletions in the locus encoding the ATAD3A, ATAD3B and ATAD3C genes. Patient cells with inherited ATAD3 defects display aberrant mitochondrial DNA organization and synthesis associated with disrupted cholesterol metabolism. Moreover drug-induced perturbations of cholesterol metabolism cause mitochondrial DNA disorganization in control cells. The interdependence of mitochondria and cholesterol homeostasis is further corroborated by the presence of mitochondrial DNA aggregation in the genetic cholesterol trafficking disorder Niemann Pick type C disease. Thus, we conclude, mitochondria are fully integrated in the circuitry of cellular cholesterol homeostasis, in which ATAD3 plays a critical role, and the dual problem of perturbed cholesterol homeostasis and mitochndrila dysfunction may be widespread in neurological and neurodegenerative diseases.
2017-06-23 | GSE86550 | GEO