Search results for "Endoplasm"
showing 10 items of 323 documents
Molecular mechanisms of endomembrane trafficking in plants
2021
Abstract Endomembrane trafficking is essential for all eukaryotic cells. The best-characterized membrane trafficking organelles include the endoplasmic reticulum (ER), Golgi apparatus, early and recycling endosomes, multivesicular body, or late endosome, lysosome/vacuole, and plasma membrane. Although historically plants have given rise to cell biology, our understanding of membrane trafficking has mainly been shaped by the much more studied mammalian and yeast models. Whereas organelles and major protein families that regulate endomembrane trafficking are largely conserved across all eukaryotes, exciting variations are emerging from advances in plant cell biology research. In this review, …
The behaviour of Bcl-2, Bax and Bcl-x in Darier's disease
2002
SummaryBackground Darier's disease (DD) is a rare autosomal dominant disorder of keratinization caused by a mutation of the ATP2A2 gene. There is little information on the behaviour of Bcl-2, Bax and Bcl-x in DD. Objectives To investigate the dynamic control and the behaviour of Bax, Bcl-2 and Bcl-x in DD. We asked whether members of the Bcl-2 family might manifest their effects through modulation of intracellular calcium signalling or whether the gene that encodes the sarco/endoplasmic reticulum Ca2+ ATPase isoform 2 (SERCA2) modulates the Bcl-2 family in the regulation of apoptosis in DD. Methods Immunohistochemical methods were used. Results There was no immunoreactivity for Bcl-2 and Bc…
Pinitol alleviates systemic inflammatory cytokines in human obesity by a mechanism involving unfolded protein response and sirtuin 1
2017
Summary Background & aims It is known that pinitol acts as a mediator of the insulin-signaling pathway, though little is known about its anti-inflammatory effect in human obesity. Therefore, this study aimed to evaluate the effect of pinitol on peripheral blood mononuclear cells (PBMCs) and visceral (VAT) and subcutaneous adipose tissues (SAT), focusing on the involvement of endoplasmic reticulum (ER) stress and sirtuin 1 (SIRT1). Methods In the intervention study, thirteen obese subjects consumed a pinitol-enriched beverage (PEB) for 12 weeks. In the ex vivo study, a biopsy of VAT and SAT was removed from thirty-four obese patients and incubated with D-pinitol for 48 h. Results The consump…
Role of Endoplasmic Reticulum and Oxidative Stress Parameters in the Pathophysiology of Disease-Related Malnutrition in Leukocytes of an Outpatient P…
2019
Cellular pathways such as inflammation or oxidative stress are the cause and triggers of disease-related malnutrition (DRM), but the influence of these markers on endoplasmic reticulum (ER) stress is unknown. The objective of this study was to analyze the relationship between mitochondrial function and ER stress parameters in a DRM population. The study population was composed of 82 outpatient subjects, of whom 45 were diagnosed with DRM and 37 were confirmed to be normonourished according to the American Society for Parenteral and Enteral Nutrition ASPEN criteria. We evaluated anthropometrical and biochemical parameters, pro-inflammatory cytokines in serum. Oxidative and ER stress markers …
Disease-associated polymorphisms in ERAP1 do not alter endoplasmic reticulum stress in patients with ankylosing spondylitis
2014
The mechanism by which human leukocyte antigen B27 (HLA-B27) contributes to ankylosing spondylitis (AS) remains unclear. Genetic studies demonstrate that association with and interaction between polymorphisms of endoplasmic reticulum aminopeptidase 1 (ERAP1) and HLA-B27 influence the risk of AS. It has been hypothesised that ERAP1-mediated HLA-B27 misfolding increases endoplasmic reticulum (ER) stress, driving an interleukin (IL) 23-dependent, pro-inflammatory immune response. We tested the hypothesis that AS-risk ERAP1 variants increase ER-stress and concomitant pro-inflammatory cytokine production in HLA-B27(+) but not HLA-B27(-) AS patients or controls. Forty-nine AS cases and 22 healthy…
Cytoskeletal Heterogeneity of an Epithelioid Sarcoma with Expression of Vimentin, Cytokeratins, and Neurofilaments
1990
We studied an unusual sarcoma with morphologic features diagnostic of epithelioid sarcoma by conventional light microscopy, transmission electron microscopy, and immunohistochemistry. The primary tumor, which was located in the deep soft tissues of the buttock of a 32-year-old woman, and its metastases to lymph nodes, liver, and lung were available for investigation. The histomorphological and ultrastructural appearance of the primary tumor and its metastatic deposits were typical of epithelioid sarcoma. Immunohistochemistry revealed a strong and uniform reactivity for vimentin in both the primary tumor and its metastases. In contrast, a marked cytoskeletal heterogeneity became evident for …
Assessment of determinants affecting the dual topology of hepadnaviral large envelope proteins
2004
For functional diversity, the large (L) envelope protein of hepatitis B virus (HBV) acquires a dual transmembrane topology via co-translational membrane integration of the S region and partial post-translational translocation of the preS subdomain. Because each process requires the second transmembrane segment (TM2), we explored the action of this determinant by using protease protection analysis of mutant L proteins. We demonstrated that neither the disruption of a leucine zipper-like motif by multiple alanine substitutions nor the flanking charges of TM2 affected the topological reorientation of L. The dispensability of both putative subunit interaction modules argues against a link betwe…
Cellular stress induces cap-independent alpha-enolase/MBP-1 translation.
2015
AbstractMyc promoter-binding protein-1 (MBP-1) is a shorter protein variant of the glycolytic enzyme alpha-enolase. Although several lines of evidence indicate that MBP-1 acts as a tumor suppressor, the cellular mechanisms and signaling pathways underlying MBP-1 expression still remain largely elusive. To dissect these pathways, we used the SkBr3 breast cancer cell line and non-tumorigenic HEK293T cells ectopically overexpressing alpha-enolase/MBP-1. Here, we demonstrate that induced cell stresses promote MBP-1 expression through the AKT/PERK/eIF2α signaling axis. Our results contribute to shedding light on the molecular mechanisms underlying MBP-1 expression in non-tumorigenic and cancer c…
Arachnid oenocytes: ecdysone synthesis in the legs of harvestmen (Opilionidae).
1981
Cells measuring up to 130 microns have been found in the proximal segments of the femora of all four pairs of walking legs in various species of harvestmen (Phalangium opilio, Leiobonum limbatum, Opilio parietinus, and Opilio ravennae). These cells exhibit all the fine-structural characteristics of insect oenocytes, in particular the conspicuous agranular endoplasmic reticulum. Radioimmunoassay after in vitro incubation of these cells has demonstrated the synthesis of alpha- and beta-ecdysone. These ecdysteroids have been found in the ovaries and tergites of the opisthosoma as well as in the oenocytes.
Sensory neuropathy with bone destruction due to a mutation in the membrane-shaping atlastin GTPase 3.
2014
Many neurodegenerative disorders present with sensory loss. In the group of hereditary sensory and autonomic neuropathies loss of nociception is one of the disease hallmarks. To determine underlying factors of sensory neurodegeneration we performed whole-exome sequencing in affected individuals with the disorder. In a family with sensory neuropathy with loss of pain perception and destruction of the pedal skeleton we report a missense mutation in a highly conserved amino acid residue of atlastin GTPase 3 (ATL3), an endoplasmic reticulum-shaping GTPase. The same mutation (p.Tyr192Cys) was identified in a second family with similar clinical outcome by screening a large cohort of 115 patients …