Structural and Functional Requirements for Agonist-induced Internalization of the Human Platelet-activating Factor Receptor

Stop) and mutations in the (D/N)P(X)2,3Y motif (Asp289 --> Asn,Ala and Tyr293 --> Phe,Ala). Chinese hamster ovary cells expressing the Cys317 --> Stop mutant exhibited a marked reduction in their capacity to internalize PAF, suggesting the existence of determinants important for endocytosis in the last 26 amino acids of the cytoplasmic tail. Substitution of Asp289 to alanine abolished both internalization and G-protein coupling, whereas substitution of Tyr293 to alanine abolished coupling but not internalization. Inhibition or activation of protein kinase C did not significantly affect the internalization process. Receptor sequestration and ligand uptake was, at least in part, blocked by concanavalin A and blockers of endocytosis mediated by clathrin-coated pits. Our data suggest that the internalization of a G-protein-coupled receptor and coupling to a G-protein can be two independent events. Moreover, the C terminus tail of hPAFR, but not the putative internalization motifs, may be involved in the internalization of hPAFR. -->

ISSN:	0021-9258
DOI:	10.1074/jbc.272.34.21289
Přístupová URL adresa:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c6392e895a55b0d26fb7fc594dc428ab https://doi.org/10.1074/jbc.272.34.21289
Rights:	OPEN
Přírůstkové číslo:	edsair.doi.dedup.....c6392e895a55b0d26fb7fc594dc428ab
Autor:	Jean-Luc Parent, Marek Rola-Pleszczynski, Christian Le Gouill, Jana Staňková
Rok vydání:	1997
Předmět:	Agonist medicine.drug_class Inositol Phosphates media_common.quotation_subject education Receptors Cell Surface CHO Cells Platelet Membrane Glycoproteins Biology Transfection Endocytosis Biochemistry Receptors G-Protein-Coupled Structure-Activity Relationship GTP-Binding Proteins Cricetinae medicine Animals Humans Platelet Activating Factor Receptor Internalization Molecular Biology Protein Kinase C Protein kinase C media_common Alanine Chinese hamster ovary cell Azepines Cell Biology Triazoles Molecular biology Recombinant Proteins Cell Compartmentation COS Cells Signal transduction Signal Transduction
Zdroj:	Journal of Biological Chemistry. 272:21289-21295
ISSN:	0021-9258
DOI:	10.1074/jbc.272.34.21289
Popis:	The receptor for platelet-activating factor (PAF) is a member of the G-protein-coupled receptor family. To study the structural elements and mechanisms involved in the internalization of human PAF receptor (hPAFR), we used the following mutants: a truncated mutant in the C-terminal tail of the receptor (Cys317 --> Stop) and mutations in the (D/N)P(X)2,3Y motif (Asp289 --> Asn,Ala and Tyr293 --> Phe,Ala). Chinese hamster ovary cells expressing the Cys317 --> Stop mutant exhibited a marked reduction in their capacity to internalize PAF, suggesting the existence of determinants important for endocytosis in the last 26 amino acids of the cytoplasmic tail. Substitution of Asp289 to alanine abolished both internalization and G-protein coupling, whereas substitution of Tyr293 to alanine abolished coupling but not internalization. Inhibition or activation of protein kinase C did not significantly affect the internalization process. Receptor sequestration and ligand uptake was, at least in part, blocked by concanavalin A and blockers of endocytosis mediated by clathrin-coated pits. Our data suggest that the internalization of a G-protein-coupled receptor and coupling to a G-protein can be two independent events. Moreover, the C terminus tail of hPAFR, but not the putative internalization motifs, may be involved in the internalization of hPAFR.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c6392e895a55b0d26fb7fc594dc428ab https://doi.org/10.1074/jbc.272.34.21289 Zobrazit plný text záznamu