Abstract
Melanocortins are known to be involved in the regulation of feeding behavior. These hormones mediate their effects through G-protein-coupled receptors by stimulating adenylate cyclase. In this study we describe the functional response of melanocortin 4 receptor (MC4R) and melanocortin 3 receptor (MC3R) in HEK 293T cells, by using a luciferase reporter gene under the transcriptional control of a cAMP-responsive element (CRE) as a monitor of intracellular cAMP levels and cAMP-regulated gene expression. We were able to show that MC4R and MC3R expressed in the human cell line HEK 293T stimulate transcription induced by stimulation with different analogs of α-melanocyte-stimulating hormone (α-MSH) at different levels. In our assay of CRE-mediated gene transcription activity, α-MSH-ND was the most efficient α-MSH analog for MC4R whereas NDP-MSH was the most efficient for MC3R. Changing the His6 residue of α-MSH-ND to Gln or Lys markedly decreased CRE-mediated luciferase activity for MC3R compared with MC4R. On analysis by modeling the receptor-ligand complex by NMR, [Gln6]α-MSH-ND and [Lys6]α-MSH-ND showed different conformational interactions between MC3R and MC4R. Furthermore, the maximum coupling efficiency of MC4R and MC3R to G proteins was different; MC4R showed only 30-50% of the maximum activity induced by MC3R. In total, our results suggest that a differential receptor-ligand interaction is involved and that the relative interactions of MC3R and MC4R with G protein are possibly quantitatively and qualitatively different.
| Original language | English |
|---|---|
| Pages (from-to) | 582-591 |
| Number of pages | 10 |
| Journal | European Journal of Biochemistry |
| Volume | 268 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2001 Sep 27 |
| Externally published | Yes |
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Keywords
- cAMP
- G protein
- Melanocortin
- Molecular modeling
- Obesity
ASJC Scopus subject areas
- Biochemistry
Cite this
Differential regulation of cAMP-mediated gene transcription and ligand selectivity by MC3R and MC4R melanocortin receptors. / Lee, Eun Jin; Lee, Soo Hyun; Jung, Jin Won; Lee, Weontae; Kim, Byung Jin; Park, Kye Won; Lim, Sung Kil; Yoon, Chang Ju; Baik, Ja-Hyun.
In: European Journal of Biochemistry, Vol. 268, No. 3, 27.09.2001, p. 582-591.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Differential regulation of cAMP-mediated gene transcription and ligand selectivity by MC3R and MC4R melanocortin receptors
AU - Lee, Eun Jin
AU - Lee, Soo Hyun
AU - Jung, Jin Won
AU - Lee, Weontae
AU - Kim, Byung Jin
AU - Park, Kye Won
AU - Lim, Sung Kil
AU - Yoon, Chang Ju
AU - Baik, Ja-Hyun
PY - 2001/9/27
Y1 - 2001/9/27
N2 - Melanocortins are known to be involved in the regulation of feeding behavior. These hormones mediate their effects through G-protein-coupled receptors by stimulating adenylate cyclase. In this study we describe the functional response of melanocortin 4 receptor (MC4R) and melanocortin 3 receptor (MC3R) in HEK 293T cells, by using a luciferase reporter gene under the transcriptional control of a cAMP-responsive element (CRE) as a monitor of intracellular cAMP levels and cAMP-regulated gene expression. We were able to show that MC4R and MC3R expressed in the human cell line HEK 293T stimulate transcription induced by stimulation with different analogs of α-melanocyte-stimulating hormone (α-MSH) at different levels. In our assay of CRE-mediated gene transcription activity, α-MSH-ND was the most efficient α-MSH analog for MC4R whereas NDP-MSH was the most efficient for MC3R. Changing the His6 residue of α-MSH-ND to Gln or Lys markedly decreased CRE-mediated luciferase activity for MC3R compared with MC4R. On analysis by modeling the receptor-ligand complex by NMR, [Gln6]α-MSH-ND and [Lys6]α-MSH-ND showed different conformational interactions between MC3R and MC4R. Furthermore, the maximum coupling efficiency of MC4R and MC3R to G proteins was different; MC4R showed only 30-50% of the maximum activity induced by MC3R. In total, our results suggest that a differential receptor-ligand interaction is involved and that the relative interactions of MC3R and MC4R with G protein are possibly quantitatively and qualitatively different.
AB - Melanocortins are known to be involved in the regulation of feeding behavior. These hormones mediate their effects through G-protein-coupled receptors by stimulating adenylate cyclase. In this study we describe the functional response of melanocortin 4 receptor (MC4R) and melanocortin 3 receptor (MC3R) in HEK 293T cells, by using a luciferase reporter gene under the transcriptional control of a cAMP-responsive element (CRE) as a monitor of intracellular cAMP levels and cAMP-regulated gene expression. We were able to show that MC4R and MC3R expressed in the human cell line HEK 293T stimulate transcription induced by stimulation with different analogs of α-melanocyte-stimulating hormone (α-MSH) at different levels. In our assay of CRE-mediated gene transcription activity, α-MSH-ND was the most efficient α-MSH analog for MC4R whereas NDP-MSH was the most efficient for MC3R. Changing the His6 residue of α-MSH-ND to Gln or Lys markedly decreased CRE-mediated luciferase activity for MC3R compared with MC4R. On analysis by modeling the receptor-ligand complex by NMR, [Gln6]α-MSH-ND and [Lys6]α-MSH-ND showed different conformational interactions between MC3R and MC4R. Furthermore, the maximum coupling efficiency of MC4R and MC3R to G proteins was different; MC4R showed only 30-50% of the maximum activity induced by MC3R. In total, our results suggest that a differential receptor-ligand interaction is involved and that the relative interactions of MC3R and MC4R with G protein are possibly quantitatively and qualitatively different.
KW - cAMP
KW - G protein
KW - Melanocortin
KW - Molecular modeling
KW - Obesity
UR - http://www.scopus.com/inward/record.url?scp=0034828356&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034828356&partnerID=8YFLogxK
U2 - 10.1046/j.1432-1327.2001.01900.x
DO - 10.1046/j.1432-1327.2001.01900.x
M3 - Article
VL - 268
SP - 582
EP - 591
JO - FEBS Journal
JF - FEBS Journal
SN - 1742-464X
IS - 3
ER -