Expression and processing of human preprogastrin in murine medullary thyroid carcinoma cells.

Abstract

Gastrin, the primary hormonal mediator of postprandial gastric acid secretion, is produced from its precursor progastrin by a series of posttranslational processing reactions including dibasic residue cleavage and carboxyl-terminal alpha-amidation. Progastrin contains three dibasic cleavage signals, Arg57Arg58, Lys74Lys75, and Arg94Arg95, that appear to be cleaved differently in different tissues. Differential processing is a potential means by which the production of biologically active peptides may be regulated in a tissue-specific manner. To study these reactions further, we used the pZipNeo SV(X) retroviral vector to express human gastrin cDNA in a heterologous cell line (MTC 6-23) known to be capable of processing other peptide precursors. The psi 2 packaging cell line transfected with the gastrin cDNA-retroviral construct (pSVXgas) produced progastrin, but no substantial amounts of processed amidated gastrin were detected. amounts of processed amidated gastrin were detected. In contrast, MTC 6-23 cells infected with the viral stock obtained from the supernatant of pSVXgas-transfected psi 2 cells produced carboxyl-terminally amidated gastrin in all of its standard molecular forms, including sulfated and nonsulfated forms of tetratriacontagastrin (G-34), heptadecagastrin (G-17), and tetradecagastrin (G-14). These studies indicate that heterologous endocrine cell lines infected with a retroviral-peptide cDNA construct can serve as useful models for peptide hormone posttranslational processing.

• Authors: D F Daugherty, C J Dickinson, T Takeuchi, D Bachwich, T Yamada
• Journal: The American journal of physiology (Am J Physiol) Vol. 260 Issue 5 Pt 1 Pg. G783-8 (May 1991) ISSN: 0002-9513 [Print] United States
• PMID: 1709790 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Gastrins
• Protein Precursors
• RNA, Messenger
• Poly A
• RNA
• preprogastrin

Topics

• Amino Acid Sequence
• Animals
• Cell Line
• Chromatography, High Pressure Liquid
• Gastrins (analysis, genetics, isolation & purification)
• Gene Expression
• Genetic Vectors
• Humans
• Immunoenzyme Techniques
• Mice
• Molecular Sequence Data
• Plasmids
• Poly A (genetics, isolation & purification)
• Protein Precursors (genetics)
• Protein Processing, Post-Translational
• RNA (genetics, isolation & purification)
• RNA, Messenger
• Radioimmunoassay
• Restriction Mapping
• Thyroid Neoplasms
• Transfection