Open AccessMonitoring of the internalization of neuropeptide Y on neuroblastoma cell line SK‐N‐MC
Author(s) -
Fabry Marlies,
Langer Michael,
RothenRutishauser Barbara,
WunderliAllenspach Heidi,
Höcker Hartwig,
BeckSickinger Annette G.
Publication year - 2000
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2000.01631.x
Subject(s) - internalization , neuropeptide y receptor , receptor , endocytosis , microbiology and biotechnology , confocal microscopy , g protein coupled receptor , extracellular , cell culture , biology , chemistry , neuropeptide , biochemistry , genetics
Neuropeptide Y (NPY) is an important neuromodulator in the central and peripheral nervous system. The peptide acts through different NPY receptor subtypes (Y1–Y5, y6) that belong to the family of G protein‐coupled receptors. In general, cellular responses to prolonged exposure to agonists of G protein‐coupled receptors are attenuated, often through internalization of the receptors and their bound ligands. In this study, a fluorescent labeled NPY derivative was synthesized and characterized to investigate the internalization of NPY in the human neuroblastoma cell line SK‐N‐MC. Internalization was proven by binding experiments and subsequent acidic washing as well as by direct visualization by means of confocal laser scanning microscopy. Approximately 20–30% of the fluorescent labeled NPY and a tritium‐marked NPY were resistant to acid removal of cell surface‐bound ligands indicating internalization. Extracellular fluorescent labeled NPY was found to be distributed heterogeneously in a clustered pattern, which suggests that the ligand‐receptor complex is collected in pits and caveolae followed by endocytosis.