Figure 2.
Functional assays in CXCR4 variants: impaired termination of CXCR4 signaling. (A) CXCR4 phosphorylation. HEK-293T cells expressing CXCR4 WT or mutants were stimulated with 100 nM rhCXCL12 for 20 minutes, and 1, 3, and 6 hours, and the whole-cell lysates were analyzed by western blot (WB) to determine CXCR4 phosphorylation (Ser324/325) and total CXCR4 levels; β-actin was used as loading control. Data show a representative WB of 4 independent experiments. (B) Stable WT and mutant CXCR4 NALM6 cells were stimulated with 100 nM rhCXCL12 for 30 minutes, and 1, 3, and 6 hours, and the surface expression of CXCR4 was measured by flow cytometry (left panel). (C) Data are expressed as precent (%) of remaining surface CXCR4. Values represent mean ± standard deviation of 5 independent experiments.