Agonist-selective, receptor-specific interaction of human P2Y receptors
with beta-arrestin-1 and -2
J Biol Chem, 283 (45):
30933-41 (November 2008)Hoffmann, Carsten Ziegler, Nicole Reiner, Susanne Krasel, Cornelius
Lohse, Martin J Research Support, Non-U.S. Gov't United States The
Journal of biological chemistry J Biol Chem. 2008 Nov 7;283(45):30933-41.
Epub 2008 Aug 14..Abstract
Interaction of G-protein-coupled receptors with beta-arrestins is
an important step in receptor desensitization and in triggering älternative"
signals. By means of confocal microscopy and fluorescence resonance
energy transfer, we have investigated the internalization of the
human P2Y receptors 1, 2, 4, 6, 11, and 12 and their interaction
with beta-arrestin-1 and -2. Co-transfection of each individual P2Y
receptor with beta-arrestin-1-GFP or beta-arrestin-2-YFP into HEK-293
cells and stimulation with the corresponding agonists resulted in
a receptor-specific interaction pattern. The P2Y(1) receptor stimulated
with ADP strongly translocated beta-arrestin-2-YFP, whereas only
a slight translocation was observed for beta-arrestin-1-GFP. The
P2Y(4) receptor exhibited equally strong translocation for beta-arrestin-1-GFP
and beta-arrestin-2-YFP when stimulated with UTP. The P2Y(6), P2Y(11),
and P2Y(12) receptor internalized only when GRK2 was additionally
co-transfected, but beta-arrestin translocation was only visible
for the P2Y(6) and P2Y(11) receptor. The P2Y(2) receptor showed a
beta-arrestin translocation pattern that was dependent on the agonist
used for stimulation. UTP translocated beta-arrestin-1-GFP and beta-arrestin-2-YFP
equally well, whereas ATP translocated beta-arrestin-1-GFP to a much
lower extent than beta-arrestin-2-YFP. The same agonist-dependent
pattern was seen in fluorescence resonance energy transfer experiments
between the fluorescently labeled P2Y(2) receptor and beta-arrestins.
Thus, the P2Y(2) receptor would be classified as a class A receptor
when stimulated with ATP or as a class B receptor when stimulated
with UTP. The ligand-specific recruitment of beta-arrestins by ATP
and UTP stimulation of P2Y(2) receptors was further found to result
in differential stimulation of ERK phosphorylation. This suggests
that the two different agonists induce distinct active states of
this receptor that show differential interactions with beta-arrestins.