Agonist induced receptor internalization of neuropeptide Y receptor subtypes depends on third intracellular loop and C-terminus.
Agonist stimulation of G-protein coupled receptors (GPCRs) results in the redistribution of the receptor from the cell surface into intracellular compartments through the process of endocytosis. Monitoring ligand-mediated internalization of GPCRs in living cells has become experimentally accessible by applying fluorescent reagents and fluorescence microscopy. By using cell lines that transiently, stably or endogenously express the human Y receptor (hYR) subtypes hY(1)R, hY(2)R, hY(4)R and hY(5)R and differently fluorescently tagged receptor proteins we were able to unravel further details concerning the internalization behavior of this multi-receptor/multi-ligand system. For the first time we could show that also the hY(2)R is internalized with a rate which is comparable to the hY(1)R and the hY(4)R. In contrast, the hY(5)R was internalized much slower and the rate remained unaffected by co-expression with other hYR subtypes. Furthermore receptor subtype co-expressing cells and selectively binding peptides revealed a receptor subtype selective internalization. By using novel hY(5)/hY(2) receptor chimera the receptor subtype dependent differences in hY receptor internalization could be identified on a molecular level.
Böhme
Ilka
I
Institute of Biochemistry, Leipzig University, Brüderstr, 34, D-04103 Leipzig, Germany.
Stichel
Jan
J
Walther
Cornelia
C
Mörl
Karin
K
Beck-Sickinger
Annette G
AG
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism; D002460:Cell Line; D004705:Endocytosis; D006801:Humans; D008164:Luminescent Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000031:analogs & derivatives / Q000737:chemistry; D017434:Protein Structure, Tertiary; D017476:Receptors, Neuropeptide Y / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship
D001426:Bacterial Proteins; D008164:Luminescent Proteins; D009478:Neuropeptide Y; D017476:Receptors, Neuropeptide Y; D011993:Recombinant Fusion Proteins; C054562:yellow fluorescent protein, Bacteria