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Signaling in chemotactic amoebae remains spatially confined to stimulated membrane regions
- Recent work has demonstrated that the receptor-mediated signaling system in chemotactic amoeboid cells shows typical properties of an excitable system. Here, we delivered spatially confined stimuli of the chemoattractant cAMP to the membrane of differentiated Dictyostelium discoideum cells to investigate whether localized receptor stimuli can induce the spreading of excitable waves in the G-protein-dependent signal transduction system. By imaging the spatiotemporal dynamics of fluorescent markers for phosphatidylinositol (3,4,5)-trisphosphate (PIP3), PTEN and filamentous actin, we observed that the activity of the signaling pathway remained spatially confined to the stimulated membrane region. Neighboring parts of the membrane were not excited and no receptor-initiated spatial spreading of excitation waves was observed. To generate localized cAMP stimuli, either particles that carried covalently bound cAMP molecules on their surface were brought into contact with the cell or a patch of the cell membrane was aspirated into a glassRecent work has demonstrated that the receptor-mediated signaling system in chemotactic amoeboid cells shows typical properties of an excitable system. Here, we delivered spatially confined stimuli of the chemoattractant cAMP to the membrane of differentiated Dictyostelium discoideum cells to investigate whether localized receptor stimuli can induce the spreading of excitable waves in the G-protein-dependent signal transduction system. By imaging the spatiotemporal dynamics of fluorescent markers for phosphatidylinositol (3,4,5)-trisphosphate (PIP3), PTEN and filamentous actin, we observed that the activity of the signaling pathway remained spatially confined to the stimulated membrane region. Neighboring parts of the membrane were not excited and no receptor-initiated spatial spreading of excitation waves was observed. To generate localized cAMP stimuli, either particles that carried covalently bound cAMP molecules on their surface were brought into contact with the cell or a patch of the cell membrane was aspirated into a glass micropipette to shield this patch against freely diffusing cAMP molecules in the surrounding medium. Additionally, the binding site of the cAMP receptor was probed with different surface-immobilized cAMP molecules, confirming results from earlier ligand-binding studies.…
Verfasserangaben: | Matthias Gerhardt, Michael Walz, Carsten BetaORCiDGND |
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DOI: | https://doi.org/10.1242/jcs.161133 |
ISSN: | 0021-9533 |
ISSN: | 1477-9137 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/25300796 |
Titel des übergeordneten Werks (Englisch): | Journal of cell science |
Verlag: | Company of Biologists Limited |
Verlagsort: | Cambridge |
Publikationstyp: | Wissenschaftlicher Artikel |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2014 |
Erscheinungsjahr: | 2014 |
Datum der Freischaltung: | 27.03.2017 |
Freies Schlagwort / Tag: | Dictyostelium; Excitable dynamics; Micropipette aspiration; PI3K; PIP2; PIP3; PTEN; Patch clamp; Signal transduction; cAMP; cAMP receptor |
Band: | 127 |
Ausgabe: | 23 |
Seitenanzahl: | 11 |
Erste Seite: | 5115 |
Letzte Seite: | 5125 |
Fördernde Institution: | Landes Brandenburg; Europaische Fond fur Regionalentwicklung Forschungsgemeinschaft [BE 3978/3-1] |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
Peer Review: | Referiert |