[Proteins associated with actin: profilin in the trophozoites of Entamoeba histolytica].

The presence and distribution of profilin, an actin binding protein that regulates the actin organization, in trophozoites of Entamoeba histolytica, strain HM1-IMSS was examined using polyclonal antibodies against calf spleen profilin. The results shows: (1) in Entamoeba extracts a peptide that comigrates with spleen profilin and representing 0.86% of the total cells proteins, (2), this peptide is immunoprecipitated by antibodies antiprofilin, and (3) stained cells with the antibodies shows the protein distributed in cortical region associated to plasma membrane and th cytoplasm. These results show that a peptide similar to spleen profilin is present in the trophozoites of E. histolytica, supporting the idea that the profilin has been conserved through evolution. The presence of this protein would be crucial in the reversible control of soluble and polymerized actin required in the amoeboid movement.