Fig 4. US27 is rapidly and constitutively internalized independent of CXCR4 or CXCL12.
(A) Live cell imaging after labeling with 100 nM membrane impermeable βRED and treatment with either PBS or 100 ng/ml CXCL12. Scale bar, 20 μm. (B) Quantification of US27 intracellular fluorescence levels in images acquired every five minutes in 3T3-US27 (gray) or 3T3-CXCR4/US27 cells (black). (C) Comparison of US27 (gray) and CXCR4 (black) internalization rates in 3T3-CXCR4/US27 cells. Error bars are standard error from average measurement of five cells.