Lpd and VASP co-localize at the phagocytic cup. (A) Schematic representation of the functional domains and binding partners of Lpd. Lpd interacts with PtdIns(3,4)P2 and VASP through its PH domain and FP4 repeats, respectively. PR, proline rich; RA, Ras-associated. (B) Representative confocal section of RAW 264.7 macrophages co-expressing Lpd (green) and VASP (red) and stained with phalloidin (blue) during phagocytic cup formation. Similar observations were made in five independent experiments. Asterisks indicate sites of particle engagement. (C) Representative confocal slice of RAW 264.7 macrophages co-expressing VASP (green) and either the Mito-AP4 (red, top row) or the Mito-FP4 (red, bottom row) constructs. Similar observations were made in three independent experiments. Asterisks indicate sites of particle binding. (D) Quantification of the phagocytic efficiency in RAW 264.7 macrophages expressing Mito-AP4 and Mito-FP4. Unpaired t test of individual phagocytic efficiency values n = 117 (Mito-AP4), n = 127 (Mito-FP4) across N = 3 independent experiments; data are means ± SEM. (E) Representative confocal micrograph of RAW 264.7 macrophages stained for VASP (green) and phalloidin (red) during phagocytosis. Insets represent the area denoted by the dotted box and particle engagement (blue). ****, P < 0.0001.
