Translational Regulation of the Vasopressin V1b Receptor Involves an Internal Ribosome Entry Site
| Autor: | Greti Aguilera, Simona Volpi, Maria Nikodemova, Cristina Rabadan-Diehl |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Receptors
Vasopressin Bryostatin 1 Blotting Western CHO Cells Regulatory Sequences Nucleic Acid Biology Transfection chemistry.chemical_compound Cricetulus Endocrinology Cell Line Tumor Cricetinae Translational regulation Animals RNA Messenger Luciferases Promoter Regions Genetic Molecular Biology Protein Kinase C Arginine vasopressin receptor 1B Reverse Transcriptase Polymerase Chain Reaction EIF4G Chinese hamster ovary cell fungi EIF4E Translation (biology) General Medicine Molecular biology Rats DNA-Binding Proteins Internal ribosome entry site chemistry Pituitary Gland Protein Biosynthesis Female 5' Untranslated Regions Ribosomes Transcription Factors |
| Zdroj: | Molecular Endocrinology. 17:1959-1971 |
| ISSN: | 1944-9917 0888-8809 |
| Popis: | Posttranscriptional mechanisms play an important role regulating pituitary levels of vasopressin V1b receptors (V1bR) during adaptation to stress. This study investigates the involvement of an internal ribosome entry site (IRES) in the 5'untranslated region (5'UTR) on V1bR translation. Transfection of bicistronic luciferase constructs into MCF-7 cells showed marked increases in translation of the second cistron after insertion of a 499-bp fragment of the V1bR 5'UTR in the intercistronic region, independently of cap-mediated translation, indicating the presence of IRES activity. IRES-mediated translation was potentiated by the protein kinase C activators, 12-O-tetradecanoylphorbol 13-acetate (PMA) and bryostatin 1, and appears to involve phosphorylation of amino terminus of eIF4G. In Chinese hamster ovary cells transfected with pV1bR-green fluorescent protein (pV1bR-GFP), PMA increased V1bR-GFP protein levels when cap-mediated translation was inhibited by rapamycin. The effect of PMA was due to increased translation because it persisted under transcriptional blockade by actinomycin D, and it was completely abolished by cycloheximide. In addition, PMA stimulated [35S]methionine incorporation into V1bR-GFP but not beta-actin in the absence of mRNA changes. The data show that regulation of IRES activity in the 5'UTR of the V1bR mRNA probably through phosphorylation of eIF4G may serve as a mechanism for rapid changes in V1bR translation to meet physiological demands. |
| Databáze: | OpenAIRE |
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