Entamoeba histolytica is a parasitic amoeba that is a leading cause of death from parasitic infections worldwide. In previous studies Upinder Singh of Stanford University, Palo Alto, Calif., et al. demonstrated that E. histolytica possesses a functional intramembrane protease of the rhomboid family of enzymes. They have now further characterized the role of this protease, EhROM1, in amoebic biology by downregulating its expression and examining phenotypes associated with amoebic pathogenesis. "We discovered that amoebas with decreased expression of EhROM1 had significant defects in their ability to attach to healthy (but not apoptotic) host cells, and had defects in ingesting both healthy and apoptotic cells," says Singh. "These results suggest that EhROM1 has roles in multiple aspects of pathogenesis. This is the first study demonstrating potential roles of rhomboid proteases in modulating parasite adhesion and phagocytosis. Thus EhROM1 may be a potential target for the development of future therapeutics and characterization of EhROM1 target(s) will be important avenues of investigation."

(L. A. Baxt, E. Rastew, R. Bracha, D. Mirelman, and U. Singh. 2010. Downregulation of an Entamoeba histolytica rhomboid protease reveals roles in regulating parasite adhesion and phagocytosis. Eukaryot. Cell 9:1283-1293.)