Avtor/Urednik | Dudanova, Irina; Sedej, Simon; Ahmad, Mohiuddin; Masius, Henriette; Sargsyan, Vardanush; Zhang, Weiqi; Riedel, Dietmar; Angenstein, Frank; Schild, Detlev; Rupnik, Marjan; Missler, Markus | |
Naslov | Important contribution of alpha-neurexins to Ca2+ - triggered exocytosis of secretory granules | |
Tip | članek | |
Vir | J Neurosci | |
Vol. in št. | Letnik 26, št. 41 | |
Leto izdaje | 2006 | |
Obseg | str. 10599-613 | |
Jezik | eng | |
Abstrakt | Alpha-Neurexins constitute a family of neuronal cell surface molecules that are essential for efficient neurotransmission, because mice lacking two or all three [alpha]-neurexin genes show a severe reduction of synaptic release. Although analyses of alpha-neurexin knock-outs and transgenic rescue animals suggested an involvement of voltage-dependent Ca2+ channels, it remained unclear whether [alpha]-neurexins have a general role in Ca2+ -dependent exocytosis and how they may affect Ca2+ channels. Here we show by membrane capacitance measurements from melanotrophs in acute pituitary gland slices that release from endocrine cellsis diminished by > 50% in adult -neurexin double knock-out and newborn triple knock-out mice. There is a reduction of the cell volume in mutant melanotrophs' however, no ultrastructural changes in size or intracellular distribution of the secretory granules were observed. Recordings of Ca2+ currents from melanotrophs, transfected human embryonic kidney cells, and brainstem neurons reveal that [alpha]-neurexins do not affect the activation or inactivation properties of Ca2+ channels directly but may be responsible for coupling them to release-ready vesicles and metabotropic receptors. Our data support a general and essential role for [alpha]-neurexins in Ca2+ -triggered exocytosis that is similarly important for secretion from neurons and endocrine cells. | |
Deskriptorji | PITUITARY GLAND EXOCYTOSIS CALCIUM CELL ADHESION MOLECULES, NEURONAL TRANSFECTION MICE, KNOCKOUT POLYMERASE CHAIN REACTION MICROSCOPY, CONFOCAL PATCH-CLAMP TECHNIQUES |