angiotensin type II receptor activity

Definition

Target type: molecularfunction

An angiotensin receptor activity that acts via Gi protein coupling and cGMP (NO) generation, and may also act via additional signaling mechanisms. [GOC:mah, PMID:10977869]

Angiotensin type II receptor activity is a molecular function associated with the angiotensin II receptor (AT2R), a G protein-coupled receptor (GPCR) that binds to angiotensin II (Ang II). Ang II is a potent vasoconstrictor and aldosterone-stimulating hormone, playing a central role in regulating blood pressure and electrolyte balance. AT2R activation initiates a signaling cascade involving G proteins, leading to diverse cellular responses. These responses are often counter-regulatory to the effects of AT1R, the other major angiotensin II receptor. Key aspects of AT2R activity include:

1. **Signal Transduction:** Upon Ang II binding, AT2R activates intracellular signaling pathways, primarily through coupling with G proteins, particularly Gq and Gi/o proteins. Gq activation triggers phospholipase C (PLC) signaling, leading to an increase in intracellular calcium levels and activation of protein kinase C (PKC). Gi/o activation inhibits adenylyl cyclase activity, leading to a decrease in cAMP levels.
2. **Vascular Effects:** Unlike AT1R, AT2R activation generally elicits vasodilatory effects. This vasodilation is mediated through various mechanisms, including nitric oxide (NO) production, modulation of vascular smooth muscle cell contractility, and suppression of reactive oxygen species (ROS) production.
3. **Cardiovascular Protection:** Studies have demonstrated that AT2R activation exerts protective effects on the cardiovascular system. It has been shown to attenuate cardiac hypertrophy, fibrosis, and apoptosis, contributing to improved cardiac function and reduced risk of heart failure.
4. **Renal Function Regulation:** AT2R activity plays a role in regulating renal function, potentially influencing processes such as sodium and water reabsorption, and promoting diuresis.
5. **Neurological Effects:** AT2R activation has been implicated in neurological functions, including modulation of neuronal excitability, neuroprotection, and cognitive function.
6. **Endocrine Effects:** AT2R activity may influence endocrine function, particularly in regulating aldosterone synthesis and release, contributing to electrolyte balance.
7. **Developmental Roles:** AT2R has been implicated in various developmental processes, including embryonic development and tissue regeneration.

The specific molecular function of AT2R activity is complex and multifaceted, involving a wide range of signaling pathways and cellular responses. Its role in regulating cardiovascular function, promoting vasodilation, and exerting protective effects on the heart and other organs makes it a potential therapeutic target for various cardiovascular diseases and other disorders.'
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Proteins (4)

Compounds (55)