Fully active chemokines from Protein Foundry can help reveal kinetics of receptor internalization and recycling.
When a chemokine binds to its G protein-coupled receptor one of the consequences of receptor activation is a decrease in the levels of receptor present on the cell surface due to more rapid internalization. The mechanism of GPCR internalization is an area of active research for many groups. Reliable methods for measuring the rate or extent of chemokine receptor internalization are of general interest, and the Marchese lab at MCW developed protocols for quantifying the change in cell surface levels of CXCR4 in response to CXCL12 activation and the recovery due to recycling. Their published protocols for flow cytometry and ELISA-based assays utilized recombinant human CXCL12 protein from Protein Foundry as the agonist to stimulate CXCR4 internalization. Check out their detailed instructions for obtaining consistent results with HEK293 and HeLa cells that express the CXCR4 receptor.
Look for future entries describing the use of Protein Foundry’s new line of fluorescently-labeled chemokines - which retain full biological activity - in a variety of research applications.