Abstract |
Proglucagon (proG) is processed in a tissue-specific manner to glucagon in the pancreas and to gilcentin, oxyntomodulin, glucagon-like peptide (GLP)-1, and GLP-2 in the intestine. Recombinant vaccinia virus (vv) vectors were used to infect prohormone convertase 1 (PC1) or PC2 into nonendocrine (BHK-proG) cells, which stably express proG. Similarly, endocrine (GH3, AtT-20) cells were coinfected with proG along with PC1 or PC2 alone, or in combination with furin, PACE4, PC5a, or PC5b. Cell extracts were analyzed for various proG-derived peptides by RIA of fractions obtained from HPLC. Upon infection of BHK-proG cells with either vv: furin or vv:PC1, glicentin was produced, while vv: PC2 did not process proG. In GH3 and AtT-20 cells, vv:PC1 produced glicentin, oxyntomodulin, GLP-1(1-37), GLP-1(7-37), and GLP-2. All other enzymes tested produced only glicentin. Interestingly, no enzyme or combination produced glucagon. Coinfection of GH3 cells with vv:PC2 and members of the chromogranin family of peptides, including chromogranin A and B and secretogranin II, as well as the PC2-binding protein 7B2, did not result in processing to glucagon. It is concluded that: 1) PC1 is responsible for the processing of proG to produce the intestinal peptides glicentin, oxyntomodulin, GLP-1(1-37), GLP-1(7-37), and GLP-2, and 2) PC2 processes proG to glicentin but does not produce glucagon, alone or in combination with other enzymes or with known molecular chaperones.
|
Authors | S Dhanvantari, N G Seidah, P L Brubaker |
Journal | Molecular endocrinology (Baltimore, Md.)
(Mol Endocrinol)
Vol. 10
Issue 4
Pg. 342-55
(Apr 1996)
ISSN: 0888-8809 [Print] United States |
PMID | 8721980
(Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Peptide Fragments
- Protein Precursors
- Recombinant Proteins
- Proglucagon
- Glucagon-Like Peptides
- Glicentin
- Glucagon
- Metallothionein
- Subtilisins
- Furin
|
Topics |
- Animals
- Cell Line
- Chromatography, High Pressure Liquid
- Cricetinae
- Furin
- Glicentin
- Glucagon
(biosynthesis, metabolism)
- Glucagon-Like Peptides
- Kidney
- Metallothionein
(genetics)
- Mice
- Peptide Fragments
(biosynthesis)
- Proglucagon
- Promoter Regions, Genetic
- Protein Precursors
(biosynthesis, metabolism)
- RNA Processing, Post-Transcriptional
- Rats
- Recombinant Proteins
(biosynthesis, metabolism)
- Subtilisins
(metabolism)
- Transfection
- Tumor Cells, Cultured
|