Figure 6.

Phg1a and Phg1b proteins are not functionally redundant. (A) Plasmids encoding chimeras composed of the extracellular domain of the Phg1a protein and the membrane portion of Phg1b (A/B fusion) or of the extracellular domain of Phg1b and the membrane portion of Phg1a (B/A fusion) were constructed. (B) Phagocytosis rate of three substrates by PHG1a knockout cells expressing either Phg1b or the B/A fusion protein was tested: 1, plain latex beads in phosphate buffer; 2, E. coli in HL5; and 3, plain latex beads in HL5. Phg1b overexpression did not complement the phagocytosis defect of PHG1a knockout cells, whereas the expression of the B/A fusion protein led to a partial complementation of the phagocytosis defect (compare with Figure 5C). These data represent the average of four independent experiments and the SD is indicated.