Calcium-dependent subquantal peptide release from single docked lawn-resident vesicles of pituitary lactotrophs
| العنوان: | Calcium-dependent subquantal peptide release from single docked lawn-resident vesicles of pituitary lactotrophs |
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| المؤلفون: | Paula P. Gonçalves, Matjaž Stenovec, Luciano Grácio, Marko Kreft, Robert Zorec |
| المصدر: | Cell calcium, vol. 109, 102687, 2023. |
| بيانات النشر: | Elsevier BV, 2023. |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Ca$^{2+}$ signalling, Physiology, secretory vesicle, konfokalna mikroskopija, Cell Biology, confocal microscopy, lactotrophs, stimulus-secretion coupling, udc:616-092, ANP.emd, Ca$^{2+}$ signalizacija, fusion pore, stimulusno-sekrecijska sklopka, Molecular Biology |
| الوصف: | Regulated exocytosis consists of the fusion between vesicles and the plasma membranes, leading to the formation of a narrow fusion pore through which secretions exit the vesicle lumen into the extracellular space. An increase in the cytosolic concentration of free Ca$^{2+}$ ([Ca$^{2+}$]$_i$) is considered the stimulus of this process. However, whether this mechanism can be preserved in a simplified system of membrane lawns with docked secretory vesicles, devoid of cellular components, is poorly understood. Here, we studied peptide discharge from individual secretory vesicles docked at the plasma membrane, prepared from primary endocrine pituitary cells (the lactotrophs), releasing hormone prolactin. To label secretory vesicles, we transfected lactotrophs to express the fluorescent atrial natriuretic peptide (ANP.emd), previously shown to be expressed in and released from prolactin-containing vesicles. We used stimulating solutions containing different [Ca$^{2+}$] to evoke vesicle peptide discharge, which appeared similar in membrane lawns and in intact stimulated lactotrophs. All vesicles examined discharged peptides in a subquantal manner, either exhibiting a unitary or sequential time course. In the membrane lawns, the unitary vesicle peptide discharge was predominant and slightly slower than that recorded in intact cells, but with a shorter delay with respect to the stimulation onset. This study revealed directly that Ca$^{2+}$ triggers peptide discharge from docked single vesicles in the membrane lawns with a half-maximal response of ∼8 µM [Ca$^{2+}$], consistent with previous whole-cell patch-clamp studies in endocrine cells where the rapid component of exocytosis, interpreted to represent docked vesicles, was fully activated at |
| وصف الملف: | application/pdf; text/url |
| تدمد: | 0143-4160 1532-1991 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a909d2729a4f119c205966fc9f07b503Test https://doi.org/10.1016/j.ceca.2022.102687Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....a909d2729a4f119c205966fc9f07b503 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 01434160 15321991 |
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