Gαs is dispensable for β-arrestin coupling but dictates GRK selectivity and is predominant for gene expression regulation by β2-adrenergic receptor.
| Publication Type | Academic Article |
| Authors | Burghi V, Paradis J, Officer A, Adame-Garcia S, Wu X, Matthees E, Barsi-Rhyne B, Ramms D, Clubb L, Acosta M, Tamayo P, Bouvier M, Inoue A, von Zastrow M, Hoffmann C, Gutkind J |
| Journal | J Biol Chem |
| Volume | 299 |
| Issue | 11 |
| Pagination | 105293 |
| Date Published | 09/27/2023 |
| ISSN | 1083-351X |
| Keywords | beta-Arrestins, Gene Expression Regulation, GTP-Binding Proteins, Receptors, Adrenergic, beta-2 |
| Abstract | β-arrestins play a key role in G protein-coupled receptor (GPCR) internalization, trafficking, and signaling. Whether β-arrestins act independently of G protein-mediated signaling has not been fully elucidated. Studies using genome-editing approaches revealed that whereas G proteins are essential for mitogen-activated protein kinase activation by GPCRs., β-arrestins play a more prominent role in signal compartmentalization. However, in the absence of G proteins, GPCRs may not activate β-arrestins, thereby limiting the ability to distinguish G protein from β-arrestin-mediated signaling events. We used β2-adrenergic receptor (β2AR) and its β2AR-C tail mutant expressed in human embryonic kidney 293 cells wildtype or CRISPR-Cas9 gene edited for Gαs, β-arrestin1/2, or GPCR kinases 2/3/5/6 in combination with arrestin conformational sensors to elucidate the interplay between Gαs and β-arrestins in controlling gene expression. We found that Gαs is not required for β2AR and β-arrestin conformational changes, β-arrestin recruitment, and receptor internalization, but that Gαs dictates the GPCR kinase isoforms involved in β-arrestin recruitment. By RNA-Seq analysis, we found that protein kinase A and mitogen-activated protein kinase gene signatures were activated by stimulation of β2AR in wildtype and β-arrestin1/2-KO cells but absent in Gαs-KO cells. These results were validated by re-expressing Gαs in the corresponding KO cells and silencing β-arrestins in wildtype cells. These findings were extended to cellular systems expressing endogenous levels of β2AR. Overall, our results support that Gs is essential for β2AR-promoted protein kinase A and mitogen-activated protein kinase gene expression signatures, whereas β-arrestins initiate signaling events modulating Gαs-driven nuclear transcriptional activity. |
| DOI | 10.1016/j.jbc.2023.105293 |
| PubMed ID | 37774973 |
| PubMed Central ID | PMC10641165 |