Actin, RhoA, and Rab11 Participation during Encystment in Entamoeba invadens

Abstract EN

In the genus Entamoeba, actin reorganization is necessary for cyst differentiation; however, its role is still unknown.

The aim of this work was to investigate the role of actin and encystation-related proteins during Entamoeba invadens encystation.

Studied proteins were actin, RhoA, a small GTPase involved through its effectors in the rearrangement of the actin cytoskeleton; Rab11, a protein involved in the transport of encystation vesicles; and enolase, as an encystment vesicles marker.

Results showed a high level of polymerized actin accompanied by increased levels of RhoA-GTP during cell rounding and loss of vacuoles.

Cytochalasin D, an actin polymerization inhibitor, and Y27632, an inhibitor of RhoA activity, reduced encystment in 80%.

These inhibitors also blocked cell rounding, disposal of vacuoles, and the proper formation of the cysts wall.

At later times, F-actin and Rab11 colocalized with enolase, suggesting that Rab11 could participate in the transport of the cyst wall components through the F-actin cytoskeleton.

These results suggest that actin cytoskeleton rearrangement is playing a decisive role in determining cell morphology changes and helping with the transport of cell wall components to the cell surface during encystment of E.

invadens.