Presence and release of SR-17 (chromogranin B(586-602)) in the porcine splenic nerve and its enzymatic degradation by CD26/dipeptidyl peptidase IV.
Using the pig splenic nerve as a model, we investigated the proteolytic processing of porcine chromogranin B (CgB) during its axonal transport. An ELISA was developed for SR-17 (CgB(586-602)), a novel CgB-derived peptide, originally found in the adrenal medulla. The results demonstrate that CgB is processed in an early stage during its axonal transport. Immunohistochemical data, based on a rabbit anti-SR-17 antiserum, show that the spleen CgB/SR-17 is exclusively present in the nerve endings. No SR-17 immunoreactivity (IR) was found in splenocytes. We also provide evidence that SR-17 is co-released with noradrenaline (NA) upon electrical stimulation of the splenic nerve. Its release is frequency-dependent and strongly enhanced in the presence of the alpha-blocking agent phentolamine. In addition, we show that the new CgB-peptide can serve as a substrate for the lymphocyte surface glycoprotein CD26, also known as dipeptidyl peptidase IV (DPP IV), generating a new peptide ER-15 (CgB(588-602)).
Depreitere
Jan
J
Laboratory of Neurobiology and Neuropharmacology, University of Antwerp, UIA, Universiteitsplein 1, B-2610 Wilrijk, Antwerp, Belgium.
Durinx
Christine
C
Wang
Zesheng
Z
Coen
Edmond
E
Lambeir
Anne-Marie
AM
Scharpé
Simon
S
De Potter
Werner
W
Nouwen
Etienne J
EJ
D000595:Amino Acid Sequence; D000818:Animals; D001370:Axonal Transport; D053378:Chromogranin B; D002864:Chromogranins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D023421:Models, Animal; D008969:Molecular Sequence Data; D009638:Norepinephrine / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D010646:Phentolamine / Q000494:pharmacology; D013154:Spleen / Q000737:chemistry / Q000294:innervation*; D013552:Swine
C506134:CHGB protein, human; D053378:Chromogranin B; D002864:Chromogranins; D010446:Peptide Fragments; D018819:Dipeptidyl Peptidase 4; D009638:Norepinephrine; D010646:Phentolamine