Jurij Dolenšek (Author), Maša Skelin (Author), Marjan Rupnik (Author)

Abstract

Exocytotic machinery in neuronal and endocrine tissues is sensitive to changesin intracellular Ca2+ concentration. Endocrine cell models, that are most frequently used to study the mechanisms of regulated exocytosis, are pancreatic beta cells, adrenal chromaffin cells and pituitary cells. To reliably study the Ca2+ sensitivity in endocrine cells, accurate and fast determination of Ca2+ dependence in each tested cell is required. With slow photo-release it is possible to induce ramp-like increase in intracellular Ca2+ concentration ([Ca2+]i) that leads to a robust exocytotic activity. Slow increases in the [Ca2+]i revealed exocytotic phases with different Ca2+ sensitivities that have been largely masked in step-like flash photo-release experiments. Strikingly, in the cells of the three described model endocrine tissues (beta, chromaffin and melanotroph cells), distinct Ca2+ sensitivity ćclassesć of secretory vesicles have been observed: a highly Ca2+-sensitive, amedium Ca2+-sensitive and a low Ca2+- sensitive kinetic phase of secretory vesicle exocytosis. We discuss that a physiological modulation of a cellular activity, e.g. by activating cAMP/PKA transduction pathway, can switch the secretory vesicles between Ca2+ sensitivity classes. This significantly alterslate steps in the secretory release of hormones even without utilizationof an additional Ca2+ sensor protein.

Keywords

Calcium sensitivity;Exocytosis;Insulin-secreting cells;Chromaffin cells;Melanotrophs;

Data

Language: English
Year of publishing:
Typology: 1.02 - Review Article
Organization: UM MF - Faculty of Medicine
UDC: 576.32/.36
COBISS: 512147512 Link will open in a new window
ISSN: 0862-8408
Views: 1489
Downloads: 51
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: English
URN: URN:SI:UM:
Type (COBISS): Other
Pages: str. S29-S38
Volume: ǂVol. ǂ60
Issue: ǂiss. ǂSuppl. 1
Chronology: 2011
Keywords (UDC): mathematics;natural sciences;naravoslovne vede;matematika;biological sciences in general;biologija;cellular and subcellular biology;cytology;celična in subcelična biologija;citologija;
ID: 1439855