ECM dimensionality tunes actin tension to regulate endoplasmic reticulum function and spheroid phenotype
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA633168 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR11799648.fastq.gz | Fastqsanger.gz | |||
| SRR11799649.fastq.gz | Fastqsanger.gz | |||
| SRR11799650.fastq.gz | Fastqsanger.gz | |||
| SRR11799651.fastq.gz | Fastqsanger.gz | |||
| SRR11799652.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 18 |
Similar Datasets
Project description:Patient-derived organoids and cellular spheroids recapitulate tissue physiology with remarkable fidelity. We investigated how engagement with a reconstituted basement membrane (rBM) in three dimensions (3D) supports the polarized, stress resilient tissue phenotype of mammary epithelial spheroids. Cells interacting with rBM in 3D had reduced levels of total and actin-associated filamin and decreased cortical actin tension that increased plasma membrane protrusions to promote negative plasma membrane curvature and plasma membrane protein associations linked to protein secretion. By contrast, cells engaging rBM in 2D had high cortical actin tension that forced filamin unfolding and endoplasmic reticulum (ER) associations. Enhanced filamin-ER interactions increased levels of PKR-like ER kinase effectors and ER-plasma membrane contact sites that compromised calcium homeostasis and diminished cell viability. Consequently, cells with low cortical actin tension had reduced ER stress and survived better. Consistently, cortical actin tension in cellular spheroids regulated polarized BM membrane deposition and sensitivity to exogenous stress. The findings implicate cortical actin tension-mediated filamin unfolding in ER function, and underscore the importance of tissue mechanics in organoid homeostasis.
2022-06-08 | GSE150695 | GEO
Project description:Patient-derived organoids and cellular spheroids recapitulate tissue physiology with remarkable fidelity. We investigated how engagement with a reconstituted basement membrane in three dimensions (3D) supports the polarized, stress resilient tissue phenotype of mammary epithelial spheroids. Cells interacting with reconstituted basement membrane in 3D had reduced levels of total and actin-associated filamin and decreased cortical actin tension that increased plasma membrane protrusions to promote negative plasma membrane curvature and plasma membrane protein associations linked to protein secretion. By contrast, cells engaging a reconstituted basement membrane in 2D had high cortical actin tension that forced filamin unfolding and endoplasmic reticulum (ER) associations. Enhanced filamin-ER interactions increased levels of PKR-like ER kinase effectors and ER-plasma membrane contact sites that compromised calcium homeostasis and diminished cell viability. Consequently, cells with decreased cortical actin tension had reduced ER stress and survived better. Consistently, cortical actin tension in cellular spheroids regulated polarized basement membrane membrane deposition and sensitivity to exogenous stress. The findings implicate cortical actin tension-mediated filamin unfolding in ER function and underscore the importance of tissue mechanics in organoid homeostasis.
| S-EPMC9434103 | biostudies-literature
Project description:Patient-derived organoids and cellular spheroids recapitulate tissue physiology with remarkable fidelity. We investigated how engagement with a reconstituted basement membrane in three dimensions (3D) supports the polarized, stress resilient tissue phenotype of mammary epithelial spheroids. Cells interacting with reconstituted basement membrane in 3D had reduced levels of total and actin-associated filamin and decreased cortical actin tension that increased plasma membrane protrusions to promote negative plasma membrane curvature and plasma membrane protein associations linked to protein secretion. By contrast, cells engaging a reconstituted basement membrane in 2D had high cortical actin tension that forced filamin unfolding and endoplasmic reticulum (ER) associations. Enhanced filamin-ER interactions increased levels of PKR-like ER kinase effectors and ER-plasma membrane contact sites that compromised calcium homeostasis and diminished cell viability. Consequently, cells with decreased cortical actin tension had reduced ER stress and survived better. Consistently, cortical actin tension in cellular spheroids regulated polarized basement membrane membrane deposition and sensitivity to exogenous stress. The findings implicate cortical actin tension-mediated filamin unfolding in ER function, and underscore the importance of tissue mechanics in organoid homeostasis.
| S-SCDT-EMBOJ-2021-109205 | biostudies-other
Project description:Yamanaka reprogramming is a stochastic process resulting in only a small fraction of somatic cells successfully converting into iPSCs. The molecular and cellular basis underlying this stochasticity remains elusive. Here we demonstrate that this stochasticity can be eliminated when ERK activity is tuned within a narrow range. This tuning can be accomplished by one tenth the concentration of MEK inhibitor in the 2i media. In the absence of pharmacologic ERK inhibition, cells fine tune ERK by morphological changes, growing taller by allocating more actin into their nucleus. A minimal cell height of 10 m is required for pluripotency, a cell geometric feature underlying the “dome-shaped” colony morphology of naïve pluripotent stem cells. Nuclear actin tunes ERK activity by binding to and immobilizing TFII-I, a transcription factor that binds and mediates ERK’s nuclear activation. This work uncovers a mechanistic link for how cell morphology controls cell identity. Insights into these fundamentally coupled processes provide effective approaches to overcome the stochasticity in reprogramming into pluripotency.
2024-01-01 | GSE229191 | GEO
Project description:Nuclear actin tunes ERK activity to promote somatic cell reprogramming into pluripotency
| PRJNA953387 | ENA
Project description:The activation of vertebrate development at fertilization relies on IP₃-dependent Ca²⁺ release, a pathway that is sensitized during oocyte maturation. This sensitization has been shown to correlate with the remodeling of the endoplasmic reticulum into large ER patches, however the mechanisms involved are not clear. Here we show that IP₃ receptors within ER patches have a higher sensitivity to IP₃ than those in the neighboring reticular ER. The lateral diffusion rate of IP₃ receptors in both ER domains is similar, and ER patches dynamically fuse with reticular ER, arguing that IP₃ receptors exchange freely between the two ER compartments. These results suggest that increasing the density of IP₃ receptors through ER remodeling is sufficient to sensitize IP₃-dependent Ca²⁺ release. Mathematical modeling supports this concept of 'geometric sensitization' of IP₃ receptors as a population, and argues that it depends on enhanced Ca²⁺-dependent cooperativity at sub-threshold IP₃ concentrations. This represents a novel mechanism of tuning the sensitivity of IP₃ receptors through ER remodeling during meiosis.
| S-EPMC3227640 | biostudies-literature
Project description:We used proximity-based biotinylation assay cells to isolate candidate plasma membrane-associated proteins whose localization are sensitive to cortical tension level. Using membrane-targeting ascorbate peroxidase (APEX2-CAAX) as a bait, we mapped the proteomic landscape at the cell cortex under high and low cortical tension conditions.
2022-06-10 | PXD018975 | Pride
Project description:Family with sequence similarity 20C (Fam20C), the physiological Golgi casein kinase, phosphorylates numerous secreted proteins that are involved in a wide variety of biological processes. However, the role of Fam20C in regulating proteins in the endoplasmic reticulum (ER) lumen is largely unknown. Here, we report that Fam20C interacts with various luminal proteins and that its depletion results in a more reduced ER lumen. We further show that ER oxidoreductin 1α (Ero1α), the pivotal sulfhydryl oxidase that catalyzes disulfide formation in the ER, is phosphorylated by Fam20C in the Golgi apparatus and retrograde-transported to the ER mediated by ERp44. The phosphorylation of Ser145 greatly enhances Ero1α oxidase activity and is critical for maintaining ER redox homeostasis and promoting oxidative protein folding. Notably, phosphorylation of Ero1α is induced under hypoxia, reductive stress, and secretion-demanding conditions such as mammalian lactation. Collectively, our findings open a door to uncover how oxidative protein folding is regulated by phosphorylation in the secretory pathway.
| S-EPMC6043849 | biostudies-literature
Project description:Early in infection, mammalian orthoreoviruses (reoviruses) build neo-organelles called viral factories (VFs). These structures incorporate fragments of endoplasmic reticulum (ER) and serve as sites of viral genome replication and particle assembly. Two reovirus nonstructural proteins, σNS and µNS, remodel the ER to produce the vesicles and tubules that form the VF matrix. Using co-immunoprecipitation assays followed by mass spectrometry, we identified annexin A2 (ANXA2), which binds actin and cellular membranes, as a host factor that interacts with reovirus nonstructural proteins. In the absence of ANXA2, VF formation was accelerated in the early phases of reovirus infection, and yields of reovirus were increased. Moreover, organization of the ER network and structure of the actin cytoskeleton were altered in the absence of ANXA2, suggesting that ANXA2 binding to actin is required to maintain ER network morphology. These findings provide evidence that interactions of reovirus nonstructural proteins directly or indirectly with ANXA2 are required for ER remodeling and formation of the membranous fragments that serve as the matrix to build reovirus factories
2025-10-29 | PXD067290 | Pride
Project description:Nuclear position is central to cell polarization, and its disruption is associated with various pathologies. The nucleus is moved away from the leading edge of migrating cells through its connection to moving dorsal actin cables, and the absence of connections to immobile ventral stress fibers. It is unclear how these asymmetric nucleo-cytoskeleton connections are established. Here, using an in vitro wound assay, we find that remodeling of endoplasmic reticulum (ER) impacts nuclear positioning through the formation of a barrier that shields immobile ventral stress fibers. The remodeling of ER and perinuclear ER accumulation is mediated by the ER shaping protein Climp-63. Furthermore, ectopic recruitment of the ER to stress fibers restores nuclear positioning in the absence of Climp-63. Our findings suggest that the ER mediates asymmetric nucleo-cytoskeleton connections to position the nucleus.
| S-EPMC9120458 | biostudies-literature