Two Basic Residues of the h-VPAC1 Receptor Second Transmembrane Helix Are Essential for Ligand Binding and Signal Transduction
| Autor: | Pascale Vertongen, M. G. Juarranz, R M Solano, Jason Perret, Ingrid Langer, Magali Waelbroeck, Patrick Robberecht |
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| Rok vydání: | 2001 |
| Předmět: |
Receptors
Vasoactive Intestinal Polypeptide Type I Vasoactive intestinal peptide CHO Cells Transfection Biochemistry Protein Structure Secondary Protein structure Cricetinae Animals Humans Receptor Molecular Biology Chemistry Lysine Chinese hamster ovary cell Cell Membrane Cell Biology Molecular biology Recombinant Proteins Transmembrane protein Kinetics Transmembrane domain Amino Acid Substitution Mutagenesis Site-Directed Receptors Vasoactive Intestinal Peptide Signal transduction hormones hormone substitutes and hormone antagonists Adenylyl Cyclases Signal Transduction Vasoactive Intestinal Peptide |
| Zdroj: | Journal of Biological Chemistry. 276:1084-1088 |
| ISSN: | 0021-9258 |
| Popis: | We mutated the vasoactive intestinal peptide (VIP) Asp(3) residue and two VPAC(1) receptor second transmembrane helix basic residues (Arg(188) and Lys(195)). VIP had a lower affinity for R188Q, R188L, K195Q, and K195I VPAC(1) receptors than for VPAC(1) receptors. [Asn(3)] VIP and [Gln(3)] VIP had lower affinities than VIP for VPAC(1) receptors but higher affinities for the mutant receptors; the two basic amino acids facilitated the introduction of the negatively charged aspartate inside the transmembrane domain. The resulting interaction was necessary for receptor activation. 1/[Asn(3)] VIP and [Gln(3)] VIP were partial agonists at VPAC(1) receptors; 2/VIP did not fully activate the K195Q, K195I, R188Q, and R188L VPAC(1) receptors; a VIP analogue ([Arg(16)] VIP) was more efficient than VIP at the four mutated receptors; and [Asn(3)] VIP and [Gln(3)] VIP were more efficient than VIP at the R188Q and R188L VPAC(1) receptors; 3/the [Asp(3)] negative charge did not contribute to the recognition of the VIP(1) antagonist, [AcHis(1),D-Phe(2),Lys(15),Arg(16),Leu(27)] VIP ()/growth hormone releasing factor (8-27). This is the first demonstration that, to activate the VPAC(1) receptor, the Asp(3) side chain of VIP must penetrate within the transmembrane domain, in close proximity to two highly conserved basic amino acids from transmembrane 2. |
| Databáze: | OpenAIRE |
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