Entamoeba histolytica, a protozoan parasite, is an important human pathogen. Diseases caused by E. histolytica include dysentery and liver abscesses and this organism is a leading parasitic cause of death on a global scale. Regulation of gene expression is a key factor that enables the parasite to adapt to the host environment during tissue invasion and to convert to the cyst stage and propagate disease outside the host. One mechanism of gene regulation in Entamoeba is a robust endogenous RNAi pathway, which controls expression of parasite genes related to virulence. However, the full repertoire of amebic biology controlled by RNAi is not known and little is known in Entamoeba about Argonaute proteins, the main protein effectors of the RNAi pathway. In E. histolytica, there are three Argonaute family genes that appear essential to amebic viability and have distinct cellular localization, hinting at unique-non overlapping functions.
We aim to study the three Argonaute proteins in E. histolytica to determine (i) whether they have slicing activity which contributes o gene silencing, and (ii) the small RNA populations that associate with EhAGO2-1 and EhAGO2-3. These data will improve our understanding of the broader scope of Argonaute proteins in RNAi and also their specific roles in E. histolytica. Our work is at the intersection of the basic cellular process of RNA-interference and amebic biology. Data that emerge will contribute to both understanding amebic pathogenesis but also to expanding the knowledge about the fundamental process of RNAi.

Public Health Relevance

Entamoeba histolytica is an important pathogen with an impact on human health on a global scale. We wish to understand the molecular mechanisms controlling amebic pathogenesis. This organism contains a robust endogenous RNAi pathway, which regulates virulence pathways. We aim to study Argonaute proteins, central to the RNAi pathway, in Entamoeba with a goal of dissecting the interplay between core RNAi components and amebic pathogenesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI115106-02
Application #
9014511
Study Section
Pathogenic Eukaryotes Study Section (PTHE)
Program Officer
Mcgugan, Glen C
Project Start
2015-02-15
Project End
2018-01-31
Budget Start
2016-02-01
Budget End
2018-01-31
Support Year
2
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Stanford University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94304