Issue Archive

Image of CXCL12-stimulated HEK-293T cells expressing a WHIM-like, green fluorescent protein (GFP)–tagged CXCR4 receptor lacking the filamin A–binding site at the third intracellular loop (X4^WHIM-ICL3ΔCt; green), and stained for lysosome-associated membrane protein 1 (LAMP1; red). WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome is a rare immunodeficiency associated with variants of the chemokine receptor CXCR4 containing mutations that lead to a hyperfunctional receptor with impaired internalization. Mutation of the filamin A–binding site at the third intracellular loop of the WHIM-like CXCR4 receptor restores ligand-induced receptor endocytosis, as seen by the colocalization (yellow) of the mutant receptor with the lysosomal marker LAMP1. The cell nuclei were counterstained with the DNA-binding dye DAPI. This image, at ×60 magnification, represents a 0.33-μm confocal plane captured on a two-laser confocal Olympus Fluoview FV-1000 microscope. See the article by Gómez-Moutón et al on page 1116.