Dibasic cleavage site is required for sorting to the regulated secretory pathway for both pro- and neuropeptide Y.
To investigate the signals governing routing of biologically active peptides to the regulated secretory pathway, we have expressed mutated and non-mutated proneuropeptide Y (ProNPY) in pituitary-derived AtT20 cells. The mutations were carried out on dibasic cleavage site and or ProNPY C-terminal sequence. Targeting to the regulated secretory pathway was studied using protein kinase A (8-BrcAMP), protein kinase C (phorbol myristate acetate) specific activators and protein synthesis inhibitor cycloheximide, and by pulse chase. The analysis of expressed peptides in cells and culture media indicated that: neuropeptide Y (NPY) and ProNPY were differently secreted, whilst NPY was exclusively secreted via regulatory pathway; ProNPY was secreted via regulated and constitutive-like secretory pathways. ProNPY secretion behaviour was not Proteolytic cleavage efficiency-dependent. The dibasic cleavage was essential for ProNPY and NPY cAMP-dependent regulated secretion and may have function as a retention signal.
Brakch
Noureddine
N
Division of Hypertension and Vascular Medicine, University Hospital, Lausanne, Switzerland. noureddine.brakch@chuv.hospvd.ch
Allemandou
Flore
F
Cavadas
Claudia
C
Grouzmann
Eric
E
Brunner
Hans R
HR
D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D009478:Neuropeptide Y / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D011498:Protein Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D021382:Protein Sorting Signals / Q000235:genetics / Q000502:physiology*; D051381:Rats
D009478:Neuropeptide Y; D011498:Protein Precursors; D021382:Protein Sorting Signals; C081158:proneuropeptide Y; D010447:Peptide Hydrolases