Repetitive N-WASP–Binding Elements of the Enterohemorrhagic Escherichia coli Effector EspFU Synergistically Activate Actin Assembly
Figure 5
EspFU repeats cause titratable increases in actin assembly in brain extract.
(A) His-EspFU-myc constructs (20 nM each) were added to Arp2/3-enriched brain extract supplemented with 2.5 µM G-actin (10% pyrene labeled), and fluorescent actin polymerization, in arbitrary units (AU), was measured over time. EspFU did not trigger actin assembly in the absence of extract (data not shown). (B) Pyrene-actin polymerization in the presence of brain extract and various concentrations of EspFU-R1-6 was measured over time. (C) Pyrene-actin polymerization in the presence of brain extract and EspFU truncations containing different repeat segments (20 nM each) was measured over time.