|Allen, M. L.,
Dobrowolski, J. M., Muller, H., Sibley, L. D. & Mansour, T. E.
(1997) Cloning and characterization of actin depolymerizing factor from Toxoplasma
gondii, Mol.Biochem.Parasitol. 88, 43-52.
|We determined the predicted amino
acid sequence of actin depolymerizing factor (ADF) from Toxoplasma
gondii by sequencing the full-length cDNA. T. gondii ADF consists of 118
amino acids (calculated molecular weight 13,400) and shares a high
degree of sequence similarity to other low molecular weight actin
monomer sequestering proteins, especially Acanthamoeba actophorin, plant
ADFs and yeast and vertebrate cofilin. ADF from T. gondii is smaller and
does not contain a nuclear localization sequence like the related
vertebrate proteins. Southern blot analysis indicates that T. gondii ADF
is a single-copy gene. Homogeneous recombinant T. gondii ADF purified
from E. coli is active in binding actin monomers and depolymerizing
F-actin. Localization of ADF by immunofluorescence and immunoelectron
microscopy indicates ADF is scattered throughout the cytoplasm and
prominently localized beneath the plasma membrane in T. gondii.