8GY7 image
Entry Detail
PDB ID:
8GY7
EMDB ID:
Title:
Cryo-EM structure of ACTH-bound melanocortin-2 receptor in complex with MRAP1 and Gs protein
Biological Source:
Host Organism:
PDB Version:
Deposition Date:
2022-09-21
Release Date:
2023-01-11
Method Details:
Experimental Method:
Resolution:
3.30 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Guanine nucleotide-binding protein G(i) subunit alpha-3,Guanine nucleotide-binding protein G(s) subunit alpha isoforms XLas
Chain IDs:A
Chain Length:361
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1
Chain IDs:B
Chain Length:371
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2
Chain IDs:C (auth: G)
Chain Length:71
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Corticotropin
Chain IDs:D (auth: M)
Chain Length:18
Number of Molecules:1
Biological Source:synthetic construct
Polymer Type:polypeptide(L)
Description:Melanocortin-2 receptor accessory protein
Chain IDs:E (auth: P)
Chain Length:184
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Soluble cytochrome b562,Adrenocorticotropic hormone receptor,melanocortin-2 receptor,Adrenocorticotropic hormone receptor,Adrenocorticotropic hormone receptor
Chain IDs:F (auth: R)
Chain Length:601
Number of Molecules:1
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Structural basis of signaling regulation of the human melanocortin-2 receptor by MRAP1.
Cell Res. 33 46 54 (2023)
PMID: 36588120 DOI: 10.1038/s41422-022-00751-6

Abstact

G protein-coupled receptors (GPCRs) are regulated by various downstream proteins, of which the melanocortin receptor accessory protein 1 (MRAP1) is closely involved in the regulation of melanocortin receptor 2 (MC2R). Assisted by MRAP1, MC2R responds to adrenocorticotropic hormone (ACTH) and stimulates glucocorticoid biogenesis and cortisol secretion. MC2R activation plays an essential role in the hypothalamic-pituitary-adrenal (HPA) axis that regulates stress response, while its dysfunction causes glucocorticoid insufficiency- or cortisol excess-associated disorders. Here, we present a cryo-electron microscopy (cryo-EM) structure of the ACTH-bound MC2R-Gs-MRAP1 complex. Our structure, together with mutagenesis analysis, reveals a unique sharp kink at the extracellular region of MRAP1 and the 'seat-belt' effect of MRAP1 on stabilizing ACTH binding and MC2R activation. Mechanisms of ACTH recognition by MC2R and receptor activation are also demonstrated. These findings deepen our understanding of GPCR regulation by accessory proteins and provide valuable insights into the ab initio design of therapeutic agents targeting MC2R.

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