Structure and function of actin depolymerizing factors of the malaria parasite and its vector

Actin depolymerizing factors (ADFs) are among the key proteins involved in regulation of actin. This study used various biochemical and structural biology methods to uncover several key aspects of ADFs from the malaria parasite and its vector, the Anopheles mosquito. The results show that ADFs from the malaria parasite can bind different phosphoinositides, which are components of the cell membrane. ADFs bind phosphoinositides by a small, positively charged surface patch, and the binding may be regulated by phosphorylation. The parasite ADFs also bind to actin in a pH dependent manner. This study also presents the three-dimensional structure of the ADF from the Anopheles mosquito. The structure is different from that of the parasite ADFs. The mosquito ADF interacts tightly with actin.