G Protein Coupled Receptors

G protein receptors mediate the cellular responses to an enormous diversity of signal molecules including hormones, neurotransmitters, and local mediators. Biological pathways involving these receptors are the targets of many drugs in current clinical use, including antihistamines, antipsychotics, antidepressants and antihypertensives.

Mechanism
Signal molecules released by nerve endings (neurotransmitters) or present in the blood (hormones) accomplish their effects on the body by interacting with receptors on cells. This interaction results in changes in the activity of enzymes within cells and modifies the cellular response.

Structure
Despite chemical and functional diversity of signal molecules that bind to them, all known G protein-coupled receptors have a similar structure and are almost certainly evolutionarily related. They consist of a single polypeptide chain that threads back and forth seven times across the phospholipid bilayer that forms the cell membrane.

Interaction of signal molecules with receptors enables the G protein to carry out intracellular actions that result in tissue responses. Signal molecules interact with their receptor subtypes distributed among various tissues such that individual signal molecules can produce different effects in different tissues.

Our Focus
We are focusing our attention and small-molecule expertise on subtypes of receptors that mediate the action of adenosine and dopamine as well as enzymes that are involved in inflammation. More specifically, our emphasis is on the A₁ and A₂A subtypes of the adenosine receptor and the D₂ subtype of the dopamine receptor. We also have drug discovery programs that target leukotriene pathways.

References and links:

• http://www.cell-biology.com/cellcom.html
• http://www.cis.upenn.edu/~krice/receptor.html

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