The SH3 domain of BMX is critical for BMX nuclear localization. A, Schematic diagram for BMX structural domains and expression constructs. GFP indicates green fluorescent protein; PH, pleckstrin homology domain; TH, TEC homology domain; K: kinase domain; aa, amino acids. Western blotting is shown in (B) using an anti‐GFP antibody to detect proteins. C, HDLECs were transfected with either 1.0 μg of GFP plasmid, GFP‐BMX full‐length plasmid (human BMX‐WT fused to an N‐terminal GFP tag), GFP‐SH2 plasmid (human BMX cDNA lacking the kinase domain fused to an N‐terminal GFP tag), GFP‐SH3 plasmid (human BMX PH, TH and SH3 domains domain fused to an N‐terminal GFP tag), GFP‐TH plasmid (human BMX PH and TH domains fused to an N‐terminal GFP tag) or GFP‐PH plasmid (human BMX PH domain fused to an N‐terminal GFP tag). IF microscopy was used to visualize the GFP tagged proteins. D, Quantification of nuclear GFP‐BMX+ cells. The data are means ± SEM from three independent experiments. One hundred GFP‐positive cells were counted for each group. ***, P < .0001. ns: non‐significant. Scale bar: 25 μm