Over-expression of NCS-1 in AtT-20 cells affects ACTH secretion and storage

• Published in: Molecular and cellular endocrinology 2001-11, Vol.184 (1), p.51-63
• Main Authors: Guild, Simon B, Murray, Aaron T, Wilson, Mary L, Wiegand, Ulrich K, Apps, David K, Jin, Yuhuai, Rindler, Michael, Roder, John, Jeromin, Andreas
• Format: Article
• Language: English
• Subjects: ACTH; Adrenocorticotropic Hormone - drug effects; Adrenocorticotropic Hormone - metabolism; Animals; Anterior pituitary; Calcium; Calcium - pharmacology; Calcium-Binding Proteins - genetics; Calcium-Binding Proteins - metabolism; Calcium-Binding Proteins - pharmacology; Corticotropin-Releasing Hormone - pharmacology; Cyclic AMP - metabolism; Dose-Response Relationship, Drug; Exocytosis; G-proteins; Gene Expression; Guanosine 5'-O-(3-Thiotriphosphate) - pharmacology; Mice; Microscopy, Confocal; Neuronal calcium sensor-1; Neuronal Calcium-Sensor Proteins; Neuropeptides - genetics; Neuropeptides - metabolism; Neuropeptides - pharmacology; Peptides; Pituitary Gland, Anterior - cytology; Transfection; Tumor Cells, Cultured; Wasp Venoms - pharmacology
• ISSN: 0303-7207; 1872-8057
• DOI: 10.1016/S0303-7207(01)00645-1

The effect of over-expressing neuronal calcium sensor 1 (NCS-1) upon stimulated adrenocorticotrophin (ACTH) secretion was studied in AtT-20 cells. Stably-transfected AtT-20 cell lines over-expressing NCS-1 were obtained and compared to wild type AtT-20 cells. Corticotrophin releasing factor (CRF-41)-stimulated ACTH secretion from NCS-1 over-expressing cells was significantly reduced from that obtained in wild type AtT-20 cells. The effects of other stimulants of ACTH secretion from wild type AtT-20 cells were not attenuated in NCS-1 over-expressing cells. Calcium, guanosine 5′- O-(3′-thiotriphosphate) (GTP-γ-S) and mastoparan stimulated ACTH secretion from permeabilised wild type AtT-20 and NCS-1 over-expressing AtT-20 cells with significantly greater ACTH secretion obtained in NCS-1 over-expressing cells. This study shows that in intact cells over-expression of NCS-1 reduces exocytotic ACTH release, while in permeabilised cells increases ACTH release. NCS-1 has multiple cellular targets and that directly and indirectly via these targets acts to increase the releasable ACTH pool while inhibiting CRF-41 stimulus–secretion coupling.