Regulated secretion is impaired in AtT-20 endocrine cells stably transfected with botulinum neurotoxin type A light chain.
Botulinum neurotoxin type A (BoNT/A) inhibits neurotransmitter release by specific cleavage of SNAP-25, a synaptosome-associated protein also expressed in the ACTH secretory cell line AtT-20. Expression of light chain BoNT/A (L-BoNT/A) gene transfected into AtT-20 cells resulted in a cleaved form of SNAP-25 indistinguishable from that generated by bona fide BoNT/A. L-BoNT/A-transfected cells showed no difference in replication rate, viability, or phenotype, compared with control AtT-20 cells. In contrast, L-BoNT/A-transfected cells could not be induced to secrete ACTH upon stimulation by 8-bromo-cAMP or KCl. In addition, alpha-latrotoxin induced ACTH release from control cells, but not from L-BoNT/A-transfected cells. These experiments suggest an important role for SNAP-25 in regulated secretion from AtT-20 cells and underline the usefulness of this cell system as a tool for the study of the molecular mechanism of peptide hormone secretion.
Aguado
F
F
Department de Biologia Cellular i Anatomia Patologica, Universitat de Barcelona, Campus de Bellvitge, c/Feixa Llarga s/n, 08907 L'Hospitalet de Llobregat, Spain.
Gombau
L
L
Majó
G
G
Marsal
J
J
Blanco
J
J
Blasi
J
J
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D019274:Botulinum Toxins, Type A / Q000235:genetics* / Q000378:metabolism; D002470:Cell Survival; D008297:Male; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D050825:Synaptosomal-Associated Protein 25; D014162:Transfection; D014407:Tumor Cells, Cultured
D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000324:Adrenocorticotropic Hormone; D019274:Botulinum Toxins, Type A