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Exchange protein directly activated by cAMP (EPAC1), a multifunctional intracellular cAMP receptor, dynamically localizes to various cellular loci, engaging with diverse molecular partners to maintain cellular homeostasis. The study investigates the role of the SUMO-interacting motif (SIM) in the subcellular targeting and cellular functions of EPAC1. It reveals that the SIM is a critical structural element for EPAC1's association with RanBP2/nucleoporin 358, a nucleoporin of the cytoplasmic filament component of the nuclear pore complex. Mutational disruption of EPAC1 SIM interferes with EPAC1's ability to activate its canonical effectors, small GTPases, Rap1 and Rap2, and noncanonical functions, such as the formation of nuclear condensates and cellular SUMOylation. Because SIM is also directly involved in cAMP binding, RanBP2's association with EPAC1 with the SIM attenuates EPAC1's cAMP binding affinity to generate an EPAC1 signaling microdomain with reduced cAMP sensitivity around the nuclear pore complex. The coupling between EPAC1's scaffold association and cAMP binding enables EPAC1 to tune its sensitivity to stress stimuli spatially depending on the cellular locations. These findings provide novel structural insights into EPAC1 signaling, highlighting the importance of SIM in EPAC1's cellular functions and potential novel strategies for therapeutically targeting EPAC1.
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http://dx.doi.org/10.1016/j.jbc.2025.110279 | DOI Listing |
Cell Signal
September 2025
Department of Anesthesiology and Operation, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, 330006, China. Electronic address:
Repeated exposure to gestational general anesthesia during pregnancy has been associated with neurodevelopmental damage and cognitive and social dysfunction in offspring. This study investigates the underlying mechanisms and therapeutic strategies for mitigating these effects. Behavioral tests revealed significant impairments in cognitive, social, and spatial learning abilities in the offspring of general anesthesia-treated mice, alongside delayed eye-opening, reduced body weight, and neuronal damage.
View Article and Find Full Text PDFPhytomedicine
August 2025
Laboratory of Neurological Disease Modeling and Translational Research, West China Hospital, Sichuan University, Chengdu, 610041, China. Electronic address:
Background: Stress is a prevalent mental health concern that often emerges in late adolescence or early adulthood. Since 2007, the Food and Drug Administration (FDA) has not approved any novel anxiolytic pharmaceuticals, leading to increased interest in nutritional supplements as alternative therapies for stress management.
Purpose: Building on our previous study, this work aims to investigate the synergistic effects of Theanine (Th) and Walnut Peptide (WP) on stress mitigation and cognitive enhancement.
Unlabelled: Glucose-dependent insulinotropic peptide receptor (GIPR) stimulates insulin release and regulates metabolic homeostasis. GIPR function is shaped by spatiotemporal trafficking of this G protein-coupled receptor (GPCR). While GPCR endocytosis is traditionally associated with β-arrestin, GIPR internalization is only modestly dependent on this pathway.
View Article and Find Full Text PDFJCI Insight
September 2025
Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.
In vitro studies have implicated orphan receptor GPRC5B in β-cell survival, proliferation and insulin secretion, but its relevance for glucose homeostasis in vivo is largely unknown. Using tamoxifen-inducible, β-cell-specific GPRC5B knockout mice (Ins-G5b-KOs) we show here that loss of GPRC5B does not affect β-cell function in the lean state, but results in strongly reduced insulin secretion and disturbed glucose tolerance in mice subjected to high fat diet for 16 weeks. Flow cytometry and single-cell expression analyses in islets from obese mice show a reduced β-cell abundance and a less mature β-cell phenotype in Ins-G5b-KOs.
View Article and Find Full Text PDFIran J Basic Med Sci
January 2025
Department of Biological Sciences in Sport and Health, Faculty of Sport Science and Health, Shahid Beheshti University, Tehran, Iran.
Objectives: This research aimed to investigate the effect of 2 types of exercise on apoptosis, neurogenesis, and angiogenesis factors in the penumbra area of stroke during the rehabilitation period after stroke.
Materials And Methods: A transient distal middle cerebral artery occlusion (td-MCAO) model was used to induce stroke and after that, the animals were randomly divided into three groups: stroke, stroke + continuous exercise with increasing duration (CTID), and stroke + exercise with increasing intensity (CTII). At 24 hr spost-stroke , MRA, neurological deficit, and behavioral tests were conducted, and also continuous exercises were conducted for five consecutive days, Finally, MRI and behavioral tests were performed, and 24 hr after that, tissue separation and blood sampling were performed to evaluate plasma irisin, Extracellular Signal-Regulated Kinases 1 and 2 (ERK1/2) / cAMP Response Element-Binding Protein (CREB) / 90 kDa Ribosomal S6 Kinase (P90RSK) pathway, Vascular Endothelial Growth Factor (VEGF) / Vascular Endothelial Growth Factor Receptor 2 (VEGF-R2), and Brain-Derived Neurotrophic Factor (BDNF) / Tropomyosin Receptor Kinase B (TrKB) levels.