Abstract
Endo-thelin (ET) receptors activate heterotrimeric G proteins that are members of the Gi; Gq, and Gs families but may also activate members of other families such as 60112/13. Gotis has multiple complex cellular effects that are similar to those of ET. We studied the ability of ET receptors to activate Gais using an assay for G protein a-chain activation that is based on the fact that an activated (GTP-bound) a-chain is resistant to trypsinization compared with an inactive (GDP-bound) a-chain. Nonhydrolyzable guanine nucleotides and AlMgF protected Ga13 from degradation by trypsin. In membranes from human embryonic kidney 293 cells that coexpress ETβ receptors and ai3, ET-3 and 5'-guanylylimidodiphosphate [Gpp(NH)p] increased the protection of 013 compared with Gpp(NH)p alone. The specificity of ETβ receptor-aja coupling was documented by showing that β2 receptors and isoproterenol or ETA receptors and ET-1 did not activate aïs and that a specific antagonist for ETβ receptors blocked ET-3-dependent activation of ai3. Copyright a> 1999 the American Physiological Society.
Original language | English (US) |
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Journal | American Journal of Physiology |
Volume | 276 |
Issue number | 4 PART 1 |
State | Published - 1999 |
Keywords
- Cell signaling
- G protein
- G protein-coupled receptor
ASJC Scopus subject areas
- Physiology (medical)