Cell-free synthesis and processing of multiple precursors to glucagon
| Autor: | Michael J. Brenner, Sara E. Roth, Thomas G. Warren, Dennis Shields |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
endocrine system
Peptide hormone Glucagon Islets of Langerhans Dogs Microsomes Protein biosynthesis Animals RNA Messenger Protein Precursors Proinsulin chemistry.chemical_classification Multidisciplinary Chemistry Fishes Translation (biology) Proglucagon Amino acid Molecular Weight Somatostatin Biochemistry Protein Biosynthesis Immunologic Techniques |
| Zdroj: | Nature. 289:511-514 |
| ISSN: | 1476-4687 0028-0836 |
| DOI: | 10.1038/289511a0 |
| Popis: | Glucagon, a polypeptide hormone of 29 amino acids, is synthesized in the islets of Langerhans and immunoreactive forms of the molecule have been found in several tissues. Like many other polypeptide hormones, glucagon is synthesized via a larger precursor molecular, proglucagon; however, estimates of its size vary considerably and the biosynthetic relationship between some of the putative precursors and authentic secreted glucagon is unclear. Consequently it was of interest to investigate the primary translation product of glucagon mRNA to relate its size to that of previously described glucagon precursors. Here we provide evidence for three distinct immunoreactive preproglucagon molecules, two of which have an apparent molecular weight (MW) of approximately 16,000 (16K). Furthermore, when microsomal membranes were present during translation, the nascent 14K preproglucagon polypeptides were processed to proglucagon with a higher apparent MW of 15,000. In contrast, the nascent 16K preproglucagon was co-translationally processed to a slightly smaller polypeptide. The data indicate that the 14K and 16K preproglucagons undergo different types of post-translational modification. |
| Databáze: | OpenAIRE |
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