The G_s alpha subunit (or Gs protein) is a heterotrimeric G protein subunit that activates the cAMP-dependent pathway by activating adenylate cyclase. Researchers have discovered that a change in the location of this protein in the brain could serve as a biomarker for depression, allowing a simple, rapid, laboratory test to identify patients with depression. ^[1]

Receptors

The G protein-coupled receptors that couple to this kind of G-protein include:

• 5-HT receptors types H₄ and H₇
• ACTH receptor
• Adenosine receptor types A_2a and A_2b
• Arginine vasopressin receptor 2
• ?-adrenergic receptors types ?₁, ?₂ and ?₃
• Calcitonin receptor
• Calcitonin gene-related peptide receptor
• Corticotropin-releasing hormone receptor
• Dopamine receptors D₁-like family (D₁ and D₅)
• FSH-receptor
• Gastric inhibitory polypeptide receptor
• Glucagon receptor
• Histamine H₂ receptor
• Luteinizing hormone/choriogonadotropin receptor
• Melanocortin receptor
• Parathyroid hormone receptor 1
• Prostaglandin receptor types D₂ and I₂
• Secretin receptor
• Thyrotropin receptor

Function

The general function of G_s is to activate adenylate cyclase, which, in turn, produces cAMP, which, in turn activates cAMP-dependent protein kinase. Further effects of G_s is thus found in function of cAMP-dependent protein kinase.

It provides a step in signal transduction. Amplification of the signal occurs for instance because the receptor activates several G_s. ^[2] However, each G_s activates only one adenylate cyclase.^[2]

See also

• Second messenger system

External links

References

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