Incubation of GH1 cells with cholera toxin for 24 h inhibits [32P]ADP-ribose incorporation into histones and non-histone nuclear proteins by more than 50%. The toxin produces a generalized decrease of incorporation into all protein acceptors and into the poly(ADP-ribosyl)ated components excised from chromatin after micrococcal nuclease digestion. The cellular levels of NAD were also decreased (40 to 80%) after treatment with cholera toxin. The inhibition of poly(ADP-ribosyl)ation is preceded by an increase of [32P]ADP-ribose incorporation, since incubation with the toxin for 3 h caused an increase instead of a decrease of incorporation. Incubation with dibutyryl cyclic AMP for 24 h also inhibited nuclear poly(ADP-ribosyl)ation, thus showing that the effect of cholera toxin might be mediated by cyclic AMP.
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http://dx.doi.org/10.1016/0006-291x(88)90523-2 | DOI Listing |
Front Cell Dev Biol
January 2025
Mechanobiology Laboratory, Nagoya University Graduate School of Medicine, Nagoya, Japan.
The high interstitial ATP concentration in the cancer microenvironment is a major source of adenosine, which acts as a strong immune suppressor. However, the source of ATP release has not been elucidated. We measured ATP release during hypotonic stress using a real-time ATP luminescence imaging system in breast cell lines and in primary cultured mammary cells.
View Article and Find Full Text PDFmBio
January 2025
Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA.
Unlabelled: Pathogenic strains cause cholera using different mechanisms. O1 and O139 serogroup strains use the toxin-co-regulated pilus (TCP) and cholera toxin (CT) for intestinal colonization and to promote secretory diarrhea, while non-O1/non-O139 serogroup strains are typically non-toxigenic and use alternate virulence factors to cause a clinically similar disease. An O39 serogroup, TCP/CT-negative strain, named AM-19226, uses a type III secretion system (T3SS) to translocate more than 10 effector proteins into the host cell cytosol.
View Article and Find Full Text PDFJ Cell Sci
January 2025
Department of Genetics, Yale School of Medicine, USA.
Retromer mediates retrograde transport of protein cargos from endosomes to the trans-Golgi network (TGN). γ-secretase is a protease that cleaves the transmembrane domain of its target proteins. Although retromer can form a stable complex with γ-secretase, the functional consequences of this interaction are not known.
View Article and Find Full Text PDFHum Vaccin Immunother
December 2025
TIMM Laboratory, Sahlgrenska Center for Cancer Research, Department of Microbiology and Immunology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
The dissemination of tumor cells with ensuing metastasis is responsible for most cancer-related deaths. Cancer vaccines may, by inducing tumor-specific effector T cells, offer a strategy to eliminate metastasizing tumor cells. However, several obstacles remain in the development of effective cancer vaccines, including the identification of adjuvants that enhance the evolvement and efficacy of tumor-specific T cells.
View Article and Find Full Text PDFMol Biol Rep
January 2025
Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Background: Lately, significant attention has been drawn towards the potential efficacy of cholera toxin (CT)-an exotoxin produced by the small intestine pathogenic bacterium Vibrio cholera-in modulating cancer-promoting events. In a recent study, we demonstrated that early-life oral administration of non-pathogenic doses of CT in mice suppressed chemically-induced carcinogenesis in tissues distantly located from the gut. In the mammary gland, CT pretreatment was shown to reduce tumor multiplicity, increase apoptosis and alter the expression of several cancer-related molecules.
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