title: The role of the C-terminus of the human hydroxycarboxylic acid receptors 2 and 3 in G protein activation using Gα-engineered yeast cells.
abstract: In the present study we focused our attention on the family of hydroxycarboxylic acid (HCA) receptors, a GPCR family of three members, of which the HCA2 and HCA3 receptors share 95% high sequence identity but differ considerably in C-terminus length with HCA3 having the longest tail. The two receptors were expressed and analysed for their activation profile in Saccharomyces cerevisiae MMY yeast strains that have different G protein Gα subunits. The hHCA2 receptor was promiscuous in its G protein coupling preference. In the presence of nicotinic acid the hHCA2 receptor activated almost all G protein pathways except Gαq (MMY14). However, the Gα protein coupling profile of the hHCA3 receptor was less promiscuous, as the receptor only activated Gαi1 (MMY23) and Gαi3 (MMY24) pathways. We then constructed two mutant receptors by 'swapping' the short (HCA2) and long (HCA3) C-terminus. The differences in HCA2 and HCA3 receptor activation and G protein selectivity were not controlled, however, by their C-terminal tails, as we observed only minor differences between mutant and corresponding wild-type receptor. This study provides new insights into the G protein coupling profiles of the HCA receptors and the function of the receptor's C terminus, which may be extended to other GPCRs.
authors.affiliation: Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Rongfang
authors.initials: R
authors.lastname: Liu
authors.affiliation: Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Jacobus P D
authors.initials: JP
authors.lastname: van Veldhoven
authors.affiliation: Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands. Electronic address: ijzerman@lacdr.leidenuniv.nl.
authors.forename: Adriaan P
authors.initials: AP
authors.lastname: IJzerman
mesh_terms: D000595:Amino Acid Sequence; D044385:GTP-Binding Protein alpha Subunits / Q000235:genetics*; D005818:Genetic Engineering; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D009154:Mutation; D043562:Receptors, G-Protein-Coupled / Q000819:agonists / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*; D013379:Substrate Specificity
chemical_list: D044385:GTP-Binding Protein alpha Subunits; C530636:HCAR2 protein, human; C473653:HCAR3 protein, human; D008024:Ligands; D043562:Receptors, G-Protein-Coupled; D011978:Receptors, Nicotinic
keywords: G protein coupling; G protein-coupled receptor; G(α)-engineered yeast cells; HCA(2); HCA(3); Hydroxycarboxylic acid receptors; LUF7159: 5-(Bis-thiophen-3-ylmethyl-amino)-1H-pyrazole-3-carboxylic acid; Nicotinic acid; acifran: 5-methyl-4-oxo-5-phenylfuran-2-carboxylic acid (PubChem CID: 51576); nicotinic acid (NA): pyridine-3-carboxylic acid (PubChem CID: 938)