Mitochondria Directly Interact with the Nuclear Pore Complex to Regulate Nuclear Energetics
Ontology highlight
ABSTRACT:
INSTRUMENT(S):
ORGANISM(S): Mus Musculus (mouse)
TISSUE(S): Fibroblast
SUBMITTER: 
Consuelo Marín-Vicente
LAB HEAD: Hesham A. Sadek
PROVIDER: PXD065792 | Pride | 2026-04-06
REPOSITORIES: Pride
Dataset's files
Items per page: 5 1 - 5 of 18 |
Similar Datasets
Project description:Differential protein expression analyzed in the studied cells and subcellular fractions.
2026-04-06 | PXD065793 | Pride
Project description:Molecular transport across the nuclear envelope in eukaryotic cells is solely controlled by the nuclear pore complex (NPC). The NPC provides two types of nucleocytoplasmic transport: passive diffusion of small molecules and active chaperon-mediated translocation of large molecules. It has been shown that the interaction between intrinsically disordered proteins that line the central channel of the NPC and the transporting cargoes is the determining factor, but the exact mechanism of transport is yet unknown. Here, we use coarse-grained molecular dynamics simulations to quantify the energy barrier that has to be overcome for molecules to pass through the NPC. We focus on two aspects of transport. First, the passive transport of model cargo molecules with different sizes is studied and the size selectivity feature of the NPC is investigated. Our results show that the transport probability of cargoes is significantly reduced when they are larger than ∼5 nm in diameter. Secondly, we show that incorporating hydrophobic binding spots on the surface of the cargo effectively decreases the energy barrier of the pore. Finally, a simple transport model is proposed which characterizes the energy barrier of the NPC as a function of diameter and hydrophobicity of the transporting particles.
| S-EPMC4764519 | biostudies-literature
Project description:Flotillin-1 and flotillin-2 are two homologous, membrane raft associated proteins. Although it has been reported that flotillins are involved in cell adhesion processes and play a role during breast cancer progression, thus making them interesting future therapeutic targets, their precise function has not been well elucidated. The present study investigates the function of these proteins in cell-cell adhesion in non-malignant cells. We have used the non-malignant epithelial MCF10A cells to study the interaction network of flotillins within cell-cell adhesion complexes. RNA interference was used to examine the effect of flotillins on the structure of adherens junctions and on the association of core proteins, such as E-cadherin, with membrane rafts. We here show that the cadherin proteins of the adherens junction associate with flotillin-2 in MCF10A cells and in various human cell lines. In vitro, flotillin-1 and flotillin-2 directly interact with γ-catenin which is so far the only protein known to be present both in the adherens junction and the desmosome. Mapping of the interaction domain within the γ-catenin sequence identified the Armadillo domains 6-8, especially ARM domain 7, to be important for the association with flotillins. Furthermore, depletion of flotillins significantly influenced the morphology of the adherens junction in human epithelial MCF10A cells and altered the association of E-cadherin and γ-catenin with membrane rafts. Taken together, these observations suggest a functional role for flotillins, especially flotillin-2, in cell-cell adhesion in non-malignant epithelial cells.
| S-EPMC3877284 | biostudies-literature
Project description:Nup358 is a protein subunit of the nuclear pore complex that recruits the opposing microtubule motors kinesin-1 and dynein [via the dynein adaptor Bicaudal D2 (BicD2)] to the nuclear envelope. This pathway is important for positioning of the nucleus during the early steps of mitotic spindle assembly and also essential for an important process in brain development. It is unknown whether dynein and kinesin-1 interact with Nup358 simultaneously or whether they compete. Here, we have reconstituted and characterized a minimal complex of kinesin-1 light chain 2 (KLC2) and Nup358. The proteins interact through a W-acidic motif in Nup358, which is highly conserved among vertebrates but absent in insects. While Nup358 and KLC2 form predominantly monomers, their interaction results in the formation of 2:2 complexes, and the W-acidic motif is required for the oligomerization. In active motor complexes, BicD2 and KLC2 each form dimers. Notably, we show that the dynein adaptor BicD2 and KLC2 interact simultaneously with Nup358, resulting in the formation of 2:2:2 complexes. Mutation of the W-acidic motif results in the formation of 1:1:1 complexes. On the basis of our data, we propose that Nup358 recruits simultaneously one kinesin-1 motor and one dynein motor via BicD2 to the nucleus. We hypothesize that the binding sites are close enough to promote direct interactions between these motor recognition domains, which may be important for the regulation of the motility of these opposing motors. Our data provide important insights into a nuclear positioning pathway that is crucial for brain development and faithful chromosome segregation.
| S-EPMC7243271 | biostudies-literature
Project description:Nucleocytoplasmic transport is sustained by karyopherins (Kaps) and a Ran guanosine triphosphate (RanGTP) gradient that imports nuclear localization signal (NLS)-specific cargoes (NLS-cargoes) into the nucleus. However, how nuclear pore complex (NPC) barrier selectivity, Kap traffic, and NLS-cargo release are systematically linked and simultaneously regulated remains incoherent. In this study, we show that Kapα facilitates Kapβ1 turnover and occupancy at the NPC in a RanGTP-dependent manner that is directly coupled to NLS-cargo release and NPC barrier function. This is underpinned by the binding affinity of Kapβ1 to phenylalanine-glycine nucleoporins (FG Nups), which is comparable with RanGTP·Kapβ1, but stronger for Kapα·Kapβ1. On this basis, RanGTP is ineffective at releasing standalone Kapβ1 from NPCs. Depleting Kapα·Kapβ1 by RanGTP further abrogates NPC barrier function, whereas adding back Kapβ1 rescues it while Kapβ1 turnover softens it. Therefore, the FG Nups are necessary but insufficient for NPC barrier function. We conclude that Kaps constitute integral constituents of the NPC whose barrier, transport, and cargo release functionalities establish a continuum under a mechanism of Kap-centric control.
| S-EPMC5674887 | biostudies-literature
Project description:Nuclear pore complexes have recently been shown to play roles in gene activation; however their potential involvement in metazoan transcription remains unclear. Here we show that the nucleoporins Sec13, Nup98, and Nup88, as well as a group of FG-repeat nucleoporins, bind to the Drosophila genome at functionally distinct loci that often do not represent nuclear envelope contact sites. Whereas Nup88 localizes to silent loci, Sec13, Nup98, and a subset of FG-repeat nucleoporins bind to developmentally regulated genes undergoing transcription induction. Strikingly, RNAi-mediated knockdown of intranuclear Sec13 and Nup98 specifically inhibits transcription of their target genes and prevents efficient reactivation of transcription after heat shock, suggesting an essential role of NPC components in regulating complex gene expression programs of multicellular organisms.
| S-EPMC2821818 | biostudies-literature
Project description:Nuclear pore complexes (NPCs) are selective transport channels embedded in the nuclear envelope. The cylindrical NPC core forms a protein coat lining a highly curved membrane opening and has a basket-like structure appended to the nucleoplasmic side. How NPCs interact with lipids, promoting membrane bending and NPC integrity, is poorly understood. Here we show that the NPC basket proteins Nup1 and Nup60 directly induce membrane curvature by amphipathic helix insertion into the lipid bilayer. In a cell-free system, both Nup1 and Nup60 transform spherical liposomes into highly curved membrane structures. In vivo, high levels of the Nup1/Nup60 amphipathic helices cause deformation of the yeast nuclear membrane, whereas adjacent helical regions contribute to anchoring the basket to the NPC core. Basket amphipathic helices are functionally linked to distinct transmembrane nucleoporins of the NPC core, suggesting a key contribution to the membrane remodeling events that underlie NPC assembly.
| S-EPMC4425464 | biostudies-literature
Project description:Nuclear pore complexes (NPCs) mediate all traffic between the nucleus and the cytoplasm and are among the most stable protein assemblies in cells. Budding yeast cells carry two variants of NPCs which differ in the presence or absence of the nuclear basket proteins Mlp1, Mlp2, and Pml39. The binding of these basket proteins occurs very late in NPC assembly and Mlp-positive NPCs are excluded from the region of the nuclear envelope that borders the nucleolus. Here, we use recombination-induced tag exchange to investigate the stability of all the NPC subcomplexes within individual NPCs. We show that the nuclear basket proteins Mlp1, Mlp2, and Pml39 remain stably associated with NPCs through multiple cell-division cycles, and that Mlp1/2 are responsible for the exclusion of NPCs from the nucleolar territory. In addition, we demonstrate that binding of the FG-nucleoporins Nup1 and Nup2 depletes also Mlp-negative NPCs from this region by an independent pathway. We develop a method for single NPC tracking in budding yeast and observe that NPCs exhibit increased mobility in the absence of nuclear basket components. Our data suggest that the distribution of NPCs on the nucleus is governed by multiple interaction of nuclear basket proteins with the nuclear interior.
| S-EPMC11617099 | biostudies-literature
Project description:The Net2, Fis1, and Dnm1 proteins are required for the division of mitochondria in the yeast Saccharomyces cerevisiae. Net2p has an amino-terminal region that contains predicted coiled-coil motifs and a carboxyl-terminal domain composed of WD-40 repeats. We found that the amino-terminal part of Net2p interacts with Fis1p, whereas the carboxyl-terminal region interacts with both Dnm1p and Fis1p. Overproduction of either domain of Net2p in yeast cells poisons mitochondrial fission, and the dominant-negative effect caused by the WD-repeats of Net2p is suppressed by increased levels of Dnm1p. Point mutations in the WD-region of Net2p or in the GTPase region of Dnm1p disrupt the normal Net2p-Dnm1p interaction, causing Net2p to lose its normal punctate distribution. Our results suggest that Dnm1p interacts with the WD-repeats of Net2p and in a GTP-dependent manner recruits Net2p to sites of mitochondrial division. Furthermore, our results indicate that Net2p is required for proper assembly of the mitochondrial fission components to regulate organelle division.
| S-EPMC207005 | biostudies-literature
Project description:NSP1 is a nuclear pore protein (nucleoporin) essential for cell growth. To identify the components that functionally interact with NSP1 in the living cell, we developed a genetic screen for mutants that are lethal in a genetic background of mutated, but not wild type NSP1. Fourteen synthetic lethal mutants were obtained, belonging to at least four different complementation groups. The genes of two complementation groups, NSP116 and NSP49, were cloned. Like the previously described nucleoporins, these genes encode proteins with many repeat sequences. NSP116 and NSP49, however, contain a new repetitive sequence motif 'GLFG', which classifies them as a subclass of nucleoporins. NSP116 and NSP49, tagged with the IgG binding domain of protein A and expressed in yeast, are located at the nuclear envelope. These data provide in vivo evidence that distinct subclasses of nucleoporins physically interact or share overlapping function in nuclear pore complexes.
| S-EPMC556983 | biostudies-other