EhCoactosin stabilizes actin filaments in the protist parasite Entamoeba histolytica.
Kumar, N., Somlata, Mazumder, M., Dutta, P., Maiti, S., Gourinath, S.(2014) PLoS Pathog 10: e1004362-e1004362
- PubMed: 25210743 
- DOI: https://doi.org/10.1371/journal.ppat.1004362
- Primary Citation of Related Structures:  
4LIZ - PubMed Abstract: 
Entamoeba histolytica is a protist parasite that is the causative agent of amoebiasis, and is a highly motile organism. The motility is essential for its survival and pathogenesis, and a dynamic actin cytoskeleton is required for this process. EhCoactosin, an actin-binding protein of the ADF/cofilin family, participates in actin dynamics, and here we report our studies of this protein using both structural and functional approaches. The X-ray crystal structure of EhCoactosin resembles that of human coactosin-like protein, with major differences in the distribution of surface charges and the orientation of terminal regions. According to in vitro binding assays, full-length EhCoactosin binds both F- and G-actin. Instead of acting to depolymerize or severe F-actin, EhCoactosin directly stabilizes the polymer. When EhCoactosin was visualized in E. histolytica cells using either confocal imaging or total internal reflectance microscopy, it was found to colocalize with F-actin at phagocytic cups. Over-expression of this protein stabilized F-actin and inhibited the phagocytic process. EhCoactosin appears to be an unusual type of coactosin involved in E. histolytica actin dynamics.
Organizational Affiliation: 
School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.