Immunological detection of prohormone convertases in two different proglucagon processing cell lines.
The distribution of the prohormone convertases, PC1/3, PC2 and PC5/6, was determined by immunoblotting in two cell lines. In alpha TC1-6 cells, the proglucagon processing occurred according to the pancreatic A-cell type. In STC-1 cells, proglucagon was processed in a manner reminiscent of the intestinal L-cell type. PC1/3 was undetectable in both proglucagon processing cell lines whereas PC2 displayed a strong immunostaining in the alpha TC1-6 cells and was barely detectable in the STC-1 cells. PC5/6 was detected as a 70 kDa protein in both cell lines. These results suggest a possible role of PC2 in the processing of proglucagon into glucagon in the A-cells, whereas in L-cells it would require still undetermined endoproteases.
Blache
P
P
Institut National de la Santé et de la Recherche Médicale, Unité 376, CCIPE, Montpellier, France.
Le-Nguyen
D
D
Boegner-Lemoine
C
C
Cohen-Solal
A
A
Bataille
D
D
Kervran
A
A
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000032:analysis / Q000378:metabolism; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D053771:Glicentin; D005934:Glucagon / Q000032:analysis / Q000378:metabolism*; D004763:Glucagon-Like Peptides / Q000032:analysis / Q000378:metabolism; D015151:Immunoblotting; D007422:Intestines / Q000201:enzymology*; D007515:Islets of Langerhans / Q000201:enzymology*; D051379:Mice; D008822:Mice, Transgenic; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D052336:Proglucagon; D045664:Proprotein Convertase 1; D045706:Proprotein Convertase 2; D043484:Proprotein Convertases; D011498:Protein Precursors / Q000032:analysis / Q000378:metabolism*; D011863:Radioimmunoassay; D013381:Subtilisins / Q000032:analysis* / Q000378:metabolism; D014407:Tumor Cells, Cultured
D010446:Peptide Fragments; D011498:Protein Precursors; D052336:Proglucagon; D004763:Glucagon-Like Peptides; D053771:Glicentin; D005934:Glucagon; D043484:Proprotein Convertases; D013381:Subtilisins; C473656:Pcsk1 protein, mouse; D045664:Proprotein Convertase 1; D045706:Proprotein Convertase 2; D016282:Aspartic Acid Endopeptidases