Gs-coupled protein receptor
The Gs-(stimulatory) protein specifically stimulates the enzyme adenylate cyclase that is attached to the cell membrane. Adenylate cyclase activity is activated when it binds to a subunit of the activated G protein. This enzyme converts ATP (adenosine triphosphate) into cyclic AMP (cAMP= cyclic adenosine monophosphate). Activation of adenylate cyclase ends when the G protein returns to the GDP-bound state.
cAMP is an important second messenger and is involved in cellular functions such as metabolism, cell division and differentiation. cAMP can initiate these functions by activating protein kinase A (PKA). Activation of this enzyme is the beginning of a cascade of enzyme activations ending with the mobilisation of the effectors that carry out the cellular functions.
The following receptors are examples of GPCRs coupling to the Gs subunit. In the TRC, the Gs coupled receptor is always represented as green receptor:
- Dopamine receptors D1-like family (D1 and D5)
- ACTH receptor
- Arginine vasopressin receptor 2
- Adrenergic β-receptors
- FSH and LH receptor
- Glucagon receptor
- Histamine H2 receptor
- TSH receptor