Search results for "nucleoplasm"
showing 7 items of 17 documents
Midregion PTHrP and Human Breast Cancer Cells
2010
PTHrP is a polyhormone undergoing proteolytic processing into smaller bioactive forms, comprising an N-terminal peptide, which is the mediator of the “classical” PTH-like effect, as well as midregion and C-terminal peptides. The midregion PTHrP domain (38-94)-amide was found to restrain growth and invasionin vitroof some breast cancer cell lines, causing striking toxicity and accelerating death; the most responsive being MDA-MB231, whose tumorigenesis was also attenuatedin vivo. In addition, midregion PTHrP appears to be imported in the nucleoplasm of cultured MDA-MB231 cells andin vitro, it can bind chromatin of metaphase spread preparations and also an isolated 20-mer oligonucleotide, the…
Itraconazole inhibits nuclear delivery of extracellular vesicle cargo by disrupting the entry of late endosomes into the nucleoplasmic reticulum
2021
ABSTRACT Extracellular vesicles (EVs) are mediators of intercellular communication under both healthy and pathological conditions, including the induction of pro‐metastatic traits, but it is not yet known how and where functional cargoes of EVs are delivered to their targets in host cell compartments. We have described that after endocytosis, EVs reach Rab7+ late endosomes and a fraction of these enter the nucleoplasmic reticulum and transport EV biomaterials to the host cell nucleoplasm. Their entry therein and docking to outer nuclear membrane occur through a tripartite complex formed by the proteins VAP‐A, ORP3 and Rab7 (VOR complex). Here, we report that the antifungal compound itracona…
Freeze-fracture features of epithelioid cells, multinucleated giant cells, and phagocytic macrophages
1987
The freeze-fracture morphology of epithelioid cells, multinucleated giant cells (Langhans' type), and phagocytic macrophages was investigated. The intensely folded and interdigitating surface membranes of epithelioid cells and multinucleated giant cells displayed no specialized areas of cell contact. The size of the intramembranous particles (IMP) and the fact that the area density of IMPs was higher in the cytoplasmic (P) faces than in the external (E) faces of the cell membranes agreed with observations in other eukaryotic cells. The area densities of the IMPs suggest lower transport rates of molecules across the cell membranes of granuloma cells than of certain epithelial cells. Small pi…
Localization of antigens PwA33 and La on lampbrush chromosomes and on nucleoplasmic structures in the oocyte of the urodele Pleurodeles waltl: Light …
1994
Monoclonal antibodies A33/22 and La11G7 have been used to study the distribution of the corre-sponding antigens, PwA33 and La, on the lampbrush chromosome loops and nucleoplasmic structures of P. waltl oocytes, using immunofluorescence, confocal laser scanning microscopy and immunogold labeling. The results obtained with these antibodies have been compared with those obtained with the Sm-antigen-specific monoclonal antibody Y12. All these monoclonal antibodies (mAbs) labeled the matrices of the majority of normal loops along their whole length. Nucleoplasmic RNP granules showed a strong staining with the mAbs La11G7 and Y12 throughout their mass, but with the mAb A33/22, they showed only a …
Cytoplasmic Parvovirus Capsids Recruit Importin Beta for Nuclear Delivery
2019
Parvoviruses are an important platform for gene and cancer therapy. Their cell entry and the following steps, including nuclear import, are inefficient, limiting their use in therapeutic applications. Two models exist on parvoviral nuclear entry: the classical import of the viral capsid using nuclear transport receptors of the importin (karyopherin) family or the direct attachment of the capsid to the nuclear pore complex leading to the local disintegration of the nuclear envelope. Here, by laser scanning confocal microscopy and in situ proximity ligation analyses combined with coimmunoprecipitation, we show that infection requires importin β-mediated access to the nuclear pore complex and …
Nuclear calcium signaling by inositol trisphosphate in GH3 pituitary cells
2008
It has been proposed that nuclear and cytosolic Ca2+ ([Ca2+]N and [Ca2+]C) may be regulated independently. We address here the issue of whether inositol trisphosphate (IP3) can, bypassing changes of [Ca2+]C, produce direct release of Ca2+ into the nucleoplasm. We have used targeted aequorins to selectively measure and compare the changes in [Ca2+]C and [Ca2+]N induced by IP3 in GH3 pituitary cells. Heparin, an IP3 inhibitor that does not permeate the nuclear pores, abolished the [Ca2+]C peaks but inhibited only partly the [Ca2+]N peaks. The permeant inhibitor 2-aminoethoxy-diphenyl-borate (2-APB) blocked both responses. Removal of ATP also inhibited more strongly the [Ca2+]C than [Ca2+]N pe…
Cytoplasmic parvovirus capsids recruit importin beta for nuclear delivery
2020
Parvoviruses are an important platform for gene and cancer therapy. Their cell entry and the following steps including nuclear import are inefficient limiting their use in therapeutic applications. Two models exist on parvoviral nuclear entry: classical import of the viral capsid using nuclear transport receptors of the importin (karyopherin) family, or direct attachment of the capsid to the nuclear pore complex leading to local disintegration of the nuclear envelope. Here, by laser scanning confocal microscopy and in situ proximity ligation analysis combined with co-immunoprecipitation we showed that infection requires importin β-mediated access into the nuclear pore complex and nucleopori…