[en] The activity of chemokine receptors is dependent on G proteins that, upon chemokine
binding, trigger various intracellular signalling cascades, as well as on b-arrestins that,
following receptor phosphorylation by GRK, orchestrate its desensitization,
endocytosis and trafficking. In addition to the 19 classical chemokine receptors, 4
receptors form a subfamily of atypical chemokine receptors (ACKR1-4) with ligand scavenging
functions (Fig 1). These receptors are unable to couple to G proteins but
their activity can be monitored via b-arrestins.
In this study we describe the NanoLux platform, a network-wide profiling platform for
chemokines and chemokines receptors based on the complementation of the
nanoluciferase (NanoBiT). This platform allows to monitor the activation, modulation
or bias of receptors or ligands by measuring the binding or the recruitment of
effectors, regulators or parners such as G proteins, GRK or b-arrestin isoforms to the
classical and the atypical chemokine receptors. For that purpose, we N-terminally
fused the LgBiT portion of Nanoluciferase to the MiniGi protein, GRK2 or human b-
arrestin 1 and 2, while the SmBiT was fused to the C terminus of all of the 23 human
chemokine receptors (Fig 2). Using this approach, we are now able to assess and
compare the activity of molecules at the chemokine-receptor network level.