Premium
Actophorin preferentially binds monomeric ADP‐Actin over ATP‐bound actin: consequences for cell locomotion
Author(s) -
Maciver Sutherland K.,
Weeds Alan G.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)00552-4
Subject(s) - actin , monomer , actin binding protein , biophysics , chemistry , actin remodeling , nucleotide , biochemistry , microfilament , microbiology and biotechnology , cytoskeleton , actin cytoskeleton , biology , cell , polymer , organic chemistry , gene
Actophorin from Acanthamoeba castellanii severs actin filaments and sequesters actin monomers. Here we report that actophorin binds ADP‐bound monomers with higher affinity than ATP‐bound monomers. Actophorin is therefore much less efficient at severing actin filaments in the presence of ADP compared to ATP, particularly taking account of the higher critical concentration in ADP. Monomer binding is also reduced in the presence of 25 mM inorganic phosphate (which is assumed to form ADP · P i ‐actin). These findings are discussed in the light of observations on the nucleotide specificity of other monomer binding proteins and related to the role of actin in lamellar protrusion and cell locomotion.