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International Journal of Molecular... Apr 2024Coatomer Protein Complex-II (COPII) mediates anterograde vesicle transport from the endoplasmic reticulum (ER) to the Golgi apparatus. Here, we report that the COPII...
Coatomer Protein Complex-II (COPII) mediates anterograde vesicle transport from the endoplasmic reticulum (ER) to the Golgi apparatus. Here, we report that the COPII coatomer complex is constructed dependent on a small GTPase, Sar1, in spermatocytes before and during male meiosis. COPII-containing foci co-localized with transitional endoplasmic reticulum (tER)-Golgi units. They showed dynamic distribution along astral microtubules and accumulated around the spindle pole, but they were not localized on the cleavage furrow (CF) sites. The depletion of the four COPII coatomer subunits, Sec16, or Sar1 that regulate COPII assembly resulted in multinucleated cell production after meiosis, suggesting that cytokinesis failed in both or either of the meiotic divisions. Although contractile actomyosin and anilloseptin rings were formed once plasma membrane ingression was initiated, they were frequently removed from the plasma membrane during furrowing. We explored the factors conveyed toward the CF sites in the membrane via COPII-mediated vesicles. DE-cadherin-containing vesicles were formed depending on Sar1 and were accumulated in the cleavage sites. Furthermore, COPII depletion inhibited de novo plasma membrane insertion. These findings suggest that COPII vesicles supply the factors essential for the anchoring and/or constriction of the contractile rings at cleavage sites during male meiosis in .
Topics: Animals; Male; Cadherins; Cell Membrane; COP-Coated Vesicles; Cytokinesis; Drosophila; Drosophila melanogaster; Drosophila Proteins; Endoplasmic Reticulum; Golgi Apparatus; Meiosis; Monomeric GTP-Binding Proteins; Spermatocytes; Vesicular Transport Proteins
PubMed: 38674111
DOI: 10.3390/ijms25084526 -
Toxins Apr 2024Cholera toxoid is an established tool for use in cellular tracing in neuroscience and cell biology. We use a sortase labeling approach to generate site-specific...
Cholera toxoid is an established tool for use in cellular tracing in neuroscience and cell biology. We use a sortase labeling approach to generate site-specific N-terminally modified variants of both the A2-B heterohexamer and B pentamer forms of the toxoid. Both forms of the toxoid are endocytosed by GM1-positive mammalian cells, and while the heterohexameric toxoid was principally localized in the ER, the B pentamer showed an unexpectedly specific localization in the medial/trans-Golgi. This study suggests a future role for specifically labeled cholera toxoids in live-cell imaging beyond their current applications in neuronal tracing and labeling of lipid rafts in fixed cells.
Topics: Humans; Cholera Toxin; Cysteine Endopeptidases; Golgi Apparatus; Animals; Bacterial Proteins; Aminoacyltransferases; Endocytosis
PubMed: 38668619
DOI: 10.3390/toxins16040194 -
Cureus Mar 2024The Golgi apparatus is an organelle responsible for protein processing, sorting, and transport in cells. Recent research has shed light on its possible role in the... (Review)
Review
The Golgi apparatus is an organelle responsible for protein processing, sorting, and transport in cells. Recent research has shed light on its possible role in the pathogenesis of various bone diseases. This review seeks to explore its significance in osteoporosis, osteogenesis imperfecta, and other bone conditions such as dysplasias. Numerous lines of evidence demonstrate that perturbations to Golgi apparatus function can disrupt post-translational protein modification, folding and trafficking functions crucial for bone formation, mineralization, and remodeling. Abnormalities related to glycosylation, protein sorting, or vesicular transport in Golgi have been associated with altered osteoblast and osteoclast function, compromised extracellular matrix composition, as well as disrupted signaling pathways involved with homeostasis of bones. Mutations or dysregulation of Golgi-associated proteins, including golgins and coat protein complex I and coat protein complex II coat components, have also been implicated in bone diseases. Such genetic alterations may disrupt Golgi structure, membrane dynamics, and protein transport, leading to bone phenotype abnormalities. Understanding the links between Golgi apparatus dysfunction and bone diseases could provide novel insights into disease pathogenesis and potential therapeutic targets. Future research should focus on unraveling specific molecular mechanisms underlying Golgi dysfunction associated with bone diseases to develop targeted interventions for restoring normal bone homeostasis while decreasing clinical manifestations associated with these issues.
PubMed: 38665758
DOI: 10.7759/cureus.56982 -
Fungal Genetics and Biology : FG & B Jun 2024Manganese and calcium homeostasis and signalling, in eukaryotic organisms, are regulated through membrane located pumps, channels and exchangers, including the Mn/Ca...
Manganese and calcium homeostasis and signalling, in eukaryotic organisms, are regulated through membrane located pumps, channels and exchangers, including the Mn/Ca uncharacterized protein family 0016 (UPF0016). Here we show that Plasmodiophora brassicae PbGDT1 is a member of the UPF0016 and an ortholog of Saccharomyces cerevisiae Gdt1p (GCR Dependent Translation Factor 1) protein involved in manganese homeostasis as well as the calcium mediated stress response in yeast. PbGDT1 complemented the ScGdt1p and ScPMR1 (Ca ATPase) double null mutant under elevated calcium stress but not under elevated manganese conditions. In both yeast and Nicotiana benthamiana, PbGDT1 localizes to the Golgi apparatus, with additional ER association in N. benthamiana. Expression of PbGDT1 in N. benthamiana, suppresses BAX-triggered cell death, further highlighting the importance of calcium homeostasis in maintaining cell physiology and integrity in a stress environment.
Topics: Nicotiana; Manganese; Calcium; Golgi Apparatus; Saccharomyces cerevisiae; Protozoan Proteins; Saccharomyces cerevisiae Proteins; Homeostasis; Calcium-Transporting ATPases; Biological Transport
PubMed: 38663635
DOI: 10.1016/j.fgb.2024.103896 -
Proceedings of the National Academy of... Apr 2024Nonalcoholic fatty liver disease, recently renamed metabolic dysfunction-associated steatotic liver disease (MASLD), is a progressive metabolic disorder that begins with...
Nonalcoholic fatty liver disease, recently renamed metabolic dysfunction-associated steatotic liver disease (MASLD), is a progressive metabolic disorder that begins with aberrant triglyceride accumulation in the liver and can lead to cirrhosis and cancer. A common variant in the gene , encoding the protein PNPLA3-I148M, is the strongest known genetic risk factor for MASLD. Despite its discovery 20 y ago, the function of PNPLA3, and now the role of PNPLA3-I148M, remain unclear. In this study, we sought to dissect the biogenesis of PNPLA3 and PNPLA3-I148M and characterize changes induced by endogenous expression of the disease-causing variant. Contrary to bioinformatic predictions and prior studies with overexpressed proteins, we demonstrate here that PNPLA3 and PNPLA3-I148M are not endoplasmic reticulum-resident transmembrane proteins. To identify their intracellular associations, we generated a paired set of isogenic human hepatoma cells expressing PNPLA3 and PNPLA3-I148M at endogenous levels. Both proteins were enriched in lipid droplet, Golgi, and endosomal fractions. Purified PNPLA3 and PNPLA3-I148M proteins associated with phosphoinositides commonly found in these compartments. Despite a similar fractionation pattern as the wild-type variant, PNPLA3-I148M induced morphological changes in the Golgi apparatus, including increased lipid droplet-Golgi contact sites, which were also observed in I148M-expressing primary human patient hepatocytes. In addition to lipid droplet accumulation, PNPLA3-I148M expression caused significant proteomic and transcriptomic changes that resembled all stages of liver disease. Cumulatively, we validate an endogenous human cellular system for investigating PNPLA3-I148M biology and identify the Golgi apparatus as a central hub of PNPLA3-I148M-driven cellular change.
Topics: Humans; Acyltransferases; Golgi Apparatus; Lipase; Lipid Droplets; Membrane Proteins; Non-alcoholic Fatty Liver Disease; Phospholipases A2, Calcium-Independent
PubMed: 38657050
DOI: 10.1073/pnas.2318619121 -
Biology Direct Apr 2024Oocyte quality is critical for the mammalian reproduction due to its necessity on fertilization and early development. During aging, the declined oocytes showing with...
BACKGROUND
Oocyte quality is critical for the mammalian reproduction due to its necessity on fertilization and early development. During aging, the declined oocytes showing with organelle dysfunction and oxidative stress lead to infertility. AMP-activated protein kinase (AMPK) is a serine/threonine protein kinase which is important for energy homeostasis for metabolism. Little is known about the potential relationship between AMPK with oocyte aging.
RESULTS
In present study we reported that AMPK was related with low quality of oocytes under post ovulatory aging and the potential mechanism. We showed the altered AMPK level during aging and inhibition of AMPK activity induced mouse oocyte maturation defect. Further analysis indicated that similar with its upstream regulator PKD1, AMPK could reduce ROS level to avoid oxidative stress in oocytes, and this might be due to its regulation on mitochondria function, since loss of AMPK activity induced abnormal distribution, reduced ATP production and mtDNA copy number of mitochondria. Besides, we also found that the ER and Golgi apparatus distribution was aberrant after AMPK inhibition, and enhanced lysosome function was also observed.
CONCLUSIONS
Taken together, these data indicated that AMPK is important for the organelle function to reduce oxidative stress during oocyte meiotic maturation.
Topics: Animals; Female; Mice; AMP-Activated Protein Kinases; Cellular Senescence; Mitochondria; Oocytes; Organelles; Oxidative Stress; Reactive Oxygen Species
PubMed: 38654312
DOI: 10.1186/s13062-024-00471-4 -
The Journal of Cell Biology May 2024The regulation of intracellular membrane traffic is coupled with the cell's need to respond to environmental stimuli, which ultimately is critical for different...
The regulation of intracellular membrane traffic is coupled with the cell's need to respond to environmental stimuli, which ultimately is critical for different processes such as cell growth and development. In this issue, Wiese et al. (https://www.doi.org/10.1083/jcb.202311125) explore the role of the trans-Golgi network (TGN) in stress response, exposing its role in mediating adaptive growth decisions.
Topics: Adaptation, Physiological; Plant Proteins; Plants; Stress, Physiological; trans-Golgi Network; Vesicular Transport Proteins
PubMed: 38652246
DOI: 10.1083/jcb.202404039 -
International Immunopharmacology May 2024Sepsis is often accompanied by multiple organ dysfunction, in which the incidence of cardiac injury is about 60%, and is closely related to high mortality. Recent...
BACKGROUND
Sepsis is often accompanied by multiple organ dysfunction, in which the incidence of cardiac injury is about 60%, and is closely related to high mortality. Recent studies have shown that Golgi stress is involved in liver injury, kidney injury, and lung injury in sepsis. However, whether it is one of the key mechanisms of sepsis-induced cardiomyopathy (SIC) is still unclear. The aim of this study is to investigate whether Golgi stress mediates SIC and the specific mechanism.
METHODS
Sepsis model of male C57BL/6J mice was established by cecal ligation and puncture. To observe the effect of Golgi stress on SIC, mice were injected with Golgi stimulant (Brefeldin A) or Golgi inhibitor (Glutathione), respectively. The 7-day survival rate of mice were recorded, and myocardial injury indicators including cardiac function, myocardial enzymes, myocardial pathological tissue score, myocardial inflammatory factors, and apoptosis were detected. The morphology of Golgi was observed by immunofluorescence, and the Golgi stress indices including GM-130, GOLPH3 and Goligin97 were detected by WB and qPCR.
RESULTS
After CLP, the cardiac function of mice was impaired and the levels of myocardial enzymes were significantly increased. Golgi stress was accompanied by increased myocardial inflammation and apoptosis. Moreover, the expressions of morphological proteins GM-130 and Golgin97 were decreased, and the expression of stress protein GOLPH3 was increased. In addition, Brefeldin A increased 7-day mortality and the above indicators in mice. The use of glutathione improves all of the above indicators.
CONCLUSION
Golgi stress mediates SIC, and the inhibition of Golgi stress can improve SIC by inhibiting apoptosis and inflammation.
Topics: Animals; Apoptosis; Male; Sepsis; Golgi Apparatus; Mice, Inbred C57BL; Cardiomyopathies; Mice; Brefeldin A; Inflammation; Disease Models, Animal; Glutathione; Myocardium; Membrane Proteins; Humans
PubMed: 38648713
DOI: 10.1016/j.intimp.2024.112103 -
Investigative Ophthalmology & Visual... Apr 2024The cGAS-STING pathway has been shown to be an important mediator of inflammation. There is emerging evidence of the importance of this signaling cascade in a variety of...
PURPOSE
The cGAS-STING pathway has been shown to be an important mediator of inflammation. There is emerging evidence of the importance of this signaling cascade in a variety of inflammatory diseases settings. Here, we present evidence that the mitochondrial DNA (mtDNA) damage-mediated cGAS-STING pathway plays an important role in the induction of inflammation in environmental dry eye (DE).
METHODS
RT-qPCR and Western blot were used to assess the induction of the cGAS-STING pathway and inflammatory cytokines in environmental DE mouse model, primary human corneal epithelial cells (pHCECs), and patients with DE. RNA sequencing was used to determine mRNA expression patterns of high osmotic pressure (HOP)-stimulated pHCECs. mtDNA was detected with electron microscopy, flow cytometry, and immunofluorescent staining. mtDNA was isolated and transfected into pHCECs for evaluating the activation of the cGAS-STING pathway.
RESULTS
The expression levels of cGAS, STING, TBK1, IRF3, and IFNβ were significantly increased in an environmental DE model and HOP-stimulated pHCECs. The STING inhibitor decreased the expression of inflammatory factors in DE. An upregulation of STING-mediated immune responses and IRF3 expression mediated by TBK1 were observed in the HOP group. HOP stimulation induced mitochondrial oxidative damage and the leakage of mtDNA into the cytoplasm. Then, mtDNA activated the cGAS-STING pathway and induced intracytoplasmic STING translocated to the Golgi apparatus. Finally, we also found activated cGAS-STING signaling in the human conjunctival blot cell of patients with DE.
CONCLUSIONS
Our findings suggest that the cGAS-STING pathway is activated by recognizing cytoplasmic mtDNA leading to STING translocation, further exacerbating the development of inflammation in environmental DE.
Topics: Animals; Female; Humans; Mice; Blotting, Western; Cells, Cultured; Disease Models, Animal; DNA, Mitochondrial; Dry Eye Syndromes; Epithelium, Corneal; Flow Cytometry; Membrane Proteins; Mice, Inbred C57BL; Nucleotidyltransferases; Real-Time Polymerase Chain Reaction; Signal Transduction
PubMed: 38648040
DOI: 10.1167/iovs.65.4.33 -
Cureus Mar 2024Overlap syndrome is a clinical challenge and brings together a wide range of treatment options for the treating physician. Addressing each and every complaint of the...
Overlap syndrome is a clinical challenge and brings together a wide range of treatment options for the treating physician. Addressing each and every complaint of the patient is crucial. A 50-year-old female patient presented with skin thickening, blackening, and hyperkeratosis; dysphagia; joint pain; features of myopathy; Raynaud's phenomenon; and dry mouth. Inflammatory markers were raised along with a positive antinuclear antibody (ANA) with Golgi apparatus pattern, anti-Sjögren's-syndrome-related antigen A (anti-SSA)/Ro60 3+, anti-SSA/Ro52 3+, and anti-PM/Scl 2+ antibodies that suggested overlap syndrome. Although the patient had no respiratory complaints, a unique interstitial lung disease (ILD) pattern was noted during the evaluation. Skin manifestations were puzzling, but the histopathology analyses of skin biopsies taken from two different sites revealed distinguishing features of cutaneous lupus and dermatomyositis. Treatment with hydroxychloroquine, pilocarpine, nifedipine, methotrexate, and topical tacrolimus produced a dramatic improvement in the clinical features. This case highlights subtle and florid features of different autoimmune diseases. The hyperkeratotic skin changes were the most striking feature, but the whole evaluation process unveiled many rare presentations of known autoimmune conditions that can open doors to new areas of our understanding toward connective tissue diseases (CTDs). Our case report demonstrates significant heterogeneity in the ANA patterns, ILD patterns, clinical manifestations, and treatment approaches.
PubMed: 38646215
DOI: 10.7759/cureus.56531