A1adenosine receptor–stimulated exocytosis in bladder umbrella cells requires phosphorylation of ADAM17 Ser-811 and EGF receptor transactivation
| Autor: | Luciana I. Gallo, Gerard Apodaca, Hui Li, Wily G. Ruiz, Kenneth R. Hallows, H. Sandeep Prakasam |
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| Rok vydání: | 2014 |
| Předmět: |
inorganic chemicals
Transcriptional Activation Small interfering RNA Urinary Bladder PKC Phosphorylation Site macromolecular substances ADAM17 Protein Biology environment and public health Exocytosis 03 medical and health sciences 0302 clinical medicine Animals Humans Phosphorylation Molecular Biology Protein kinase C 030304 developmental biology 0303 health sciences Receptor Adenosine A1 Kinase Receptor transactivation Epithelial Cells Articles Cell Biology Adenosine receptor Molecular biology Rats 3. Good health Cell biology ErbB Receptors enzymes and coenzymes (carbohydrates) ADAM Proteins Membrane Trafficking bacteria 030217 neurology & neurosurgery |
| Zdroj: | Molecular Biology of the Cell |
| ISSN: | 1939-4586 1059-1524 |
| Popis: | The role of phosphorylation in ADAM17-dependent shedding is controversial. We show that the A1 adenosine receptor stimulates exocytosis in umbrella cells by a pathway that requires phosphorylation of ADAM17–Ser-811, followed by HB-EGF shedding and EGF receptor transactivation. Preventing ADAM17 phosphorylation blocks these downstream events. Despite the importance of ADAM17-dependent cleavage in normal biology and disease, the physiological cues that trigger its activity, the effector pathways that promote its function, and the mechanisms that control its activity, particularly the role of phosphorylation, remain unresolved. Using native bladder epithelium, in some cases transduced with adenoviruses encoding small interfering RNA, we observe that stimulation of apically localized A1 adenosine receptors (A1ARs) triggers a Gi-Gβγ-phospholipase C-protein kinase C (PKC) cascade that promotes ADAM17-dependent HB-EGF cleavage, EGFR transactivation, and apical exocytosis. We further show that the cytoplasmic tail of rat ADAM17 contains a conserved serine residue at position 811, which resides in a canonical PKC phosphorylation site, and is phosphorylated in response to A1AR activation. Preventing this phosphorylation event by expression of a nonphosphorylatable ADAM17S811A mutant or expression of a tail-minus construct inhibits A1AR-stimulated, ADAM17-dependent HB-EGF cleavage. Furthermore, expression of ADAM17S811A in bladder tissues impairs A1AR-induced apical exocytosis. We conclude that adenosine-stimulated exocytosis requires PKC- and ADAM17-dependent EGFR transactivation and that the function of ADAM17 in this pathway depends on the phosphorylation state of Ser-811 in its cytoplasmic domain. |
| Databáze: | OpenAIRE |
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