Receptor crosstalk protein, calcyon, regulates affinity state of dopamine D1 receptors
| Autor: | Michael S. Lidow, Amy Roberts, Ling Zhang, Phil Ok Koh, Nelson Lezcano, Clare Bergson |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
medicine.medical_specialty
Apomorphine D1-like receptor Biology Tritium Binding Competitive Cell Line Radioligand Assay Dopamine receptor D1 Dopamine receptor D3 Internal medicine Dopamine receptor D2 medicine Humans Receptor Pharmacology Dose-Response Relationship Drug Receptors Dopamine D1 Membrane Proteins Receptor Cross-Talk Benzazepines Cell biology Endocrinology D2-like receptor Dopamine receptor Dopamine Agonists Dopamine Antagonists Carbachol Guanosine Triphosphate Endogenous agonist |
| Zdroj: | European Journal of Pharmacology. 427:187-193 |
| ISSN: | 0014-2999 |
| Popis: | The recently cloned protein, calcyon, potentiates crosstalk between G(s)-coupled dopamine D1 receptors and heterologous G(q/11)-coupled receptors allowing dopamine D1 receptors to stimulate intracellular Ca(2+) release, in addition to cAMP production. This crosstalk also requires the participating G(q/11)-coupled receptors to be primed by their agonists. We examined the ability of calcyon and priming to regulate the affinity of dopamine D1 receptors for its ligands. Receptor binding assays were performed on HEK293 cell membrane preparations expressing dopamine D1 receptors either alone or in combination with calcyon. Co-expression of dopamine D1 receptor and calcyon affected neither the affinity of this receptor for antagonists nor the affinity of agonist binding to this receptor high and low-affinity states. However, the presence of calcyon dramatically decreased the proportion of the high-affinity dopamine D1 receptor agonist binding sites. This decrease was reversed by carbachol, which primes the receptor crosstalk by stimulating endogenous G(q/11)-coupled muscarinic receptors. Our findings suggest that calcyon regulates the ability of dopamine D1 receptors to achieve the high-affinity state for agonists, in a manner that depends on priming of receptor crosstalk. |
| Databáze: | OpenAIRE |
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