Differential expression and regulation of AE2 anion exchanger subtypes in rabbit parietal and mucous cells
| Autor: | Heidi Rossmann, Ursula Seidler, Seth L. Alper, Alan K. Stuart-Tilley, Oliver Bachmann, Gary E. Shull, Brigitte Obermaier, Zhuo Wang |
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| Rok vydání: | 2001 |
| Předmět: |
Gene isoform
Cell type Physiology Sequence analysis SLC4A Proteins Anion Transport Proteins Immunoblotting Molecular Sequence Data Biology Antiporters chemistry.chemical_compound Parietal Cells Gastric Gastric mucosa medicine Consensus sequence Animals Protein Isoforms Tissue Distribution Amino Acid Sequence RNA Messenger Peptide sequence Protein kinase C Forskolin Reverse Transcriptase Polymerase Chain Reaction Membrane Proteins Original Articles Blotting Northern Molecular biology Immunohistochemistry humanities medicine.anatomical_structure chemistry Microscopy Fluorescence Gastric Mucosa Rabbits |
| Zdroj: | The Journal of physiology. 534(Pt 3) |
| ISSN: | 0022-3751 |
| Popis: | 1. The anion exchanger isoform 2 (AE2) gene encodes three subtypes (AE2a, b and c), which have different N-termini and tissue distributions. AE2 is expressed at high levels in the stomach, where it is thought to mediate basolateral base exit during acid production. The present study investigated if the three AE2 subtypes are differentially expressed and regulated in different cell types within the gastric mucosa. 2. The cloning strategy to obtain rabbit AE2a, b and c cDNAs combined genomic PCR and RT-PCR based on primers deduced from the rat sequences. Semiquantitative RT-PCR using homologous primers revealed much higher AE2 mRNA expression in rabbit parietal cells (PCs) than in mucous cells (MCs). The subtype expression pattern was AE2b >> AE2c > or = AE2a in PCs and AE2a >AE2b >> AE2c in MCs. Sequence analysis revealed the presence of a highly conserved protein kinase C (PKC) consensus sequence in the AE2a alternative N-terminus. 3. Maximal Cl(-)-HCO(3)(-) exchange rates, measured fluorometrically in BCECF-loaded cultured gastric cells, were much higher in PCs than MCs. PKC activation by phorbol ester stimulated maximal Cl(-)-HCO(3)(-) exchange rates in MCs but not in PCs, whereas forskolin had no effect in each cell type. 4. In summary, rabbit PCs and MCs, which originate from the same gastric stem cell population, display a completely different AE2 subtype expression pattern. Therefore, AE2 subtype expression is not organ specific but cell type specific. The different regulation of anion exchange in parietal and mucous cells suggests that AE2 subtypes may be differentially regulated. |
| Databáze: | OpenAIRE |
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