Shining a light on dense granules- biochemical, genetic and cell biological investigation of an essential but understudied compartment in malarial -

Lead Research Organisation: London Sch of Hygiene and Trop Medicine
Department Name: Infectious and Tropical Diseases

Abstract

- parasites

Research Questions:
The proposed project aims to use interdisciplinary techniques to investigate dense granule formation and protein targeting in the apicomplexan parasite Plasmodium falciparum, the most lethal of the human malaria parasites. Molecular biological approaches and imaging techniques will be used to identify genetic sequences which target proteins to the dense granules. Once these signals have been identified, bioinformatics approaches will be used to predict novel dense granule proteins. The use of such bioinformatics techniques meets the MRC LID key skills of data analytics, informatics and computational approaches. The presence of these proteins can then be confirmed using mass spectrometry, and their function determined by observing knock-out mutants generated using CRISPR/Cas9 genome editing technology.

Rationale:
Dense granules are essential for Plasmodium infection of the host erythrocyte. Since the debilitating symptoms of malaria are a product of parasite invasion and survival within the host erythrocytes, elucidating the mechanisms which underly this process and contributing to the understanding of Plasmodium systems biology will provide information of great importance to medical science. Additionally, this project could identify proteins suitable for inhibitor screening with a view to discovering compounds capable of inhibiting parasite growth.

Background:
Malaria is a significant infectious disease caused by apicomplexan parasites of the genus Plasmodium with 216 million cases and an estimated 445,000 mortalities worldwide in 2016 , and 65% of cases occurring in those under the age of 15. However, advances against malaria are in decline, therefore the development of novel interventions is vital.
The symptoms of malaria are caused when the infective life stage of the parasite Plasmodium (the zoite), invades the host erythrocyte and forms a parasitophorous vacuole (PV) in which the parasite can reproduce. As in other apicomplexan parasites, Plasmodium spp. invasion of the host cell by the zoite requires the function of three specialised secretory organelles; micronemes, rhoptries, and dense granules (DG). These three organelles have been demonstrated to be essential to host cell invasion and PV formation, with rhoptries and micronemes holding essential roles in host cell invasion in Plasmodium. However, despite their vital role in parasite survival, the mechanisms of DG function in Plasmodium host cell infection remain largely unknown.

Publications

10 25 50