CHEMICAL AND GENETIC INTERROGATION OF NOVEL PROTEOLTYTIC PATHWAYS IN APICOPLEXAN PARASITES

Basic research on the molecular mechanisms that control apicoplexan parasite development is required to better understand the biology of these human and livestock pathogens. The objective of this proposal is to combine genetic and chemical approaches to identify novel proteolytic pathways in Plasmodium falciparum. In particular, we will interrogate the biological function of conserved plasmodium proteases that have not yet been investigated, namely prolyl oligopeptidases and retropepsin-like proteases. Genetic methods allow exquisite specificity, however they do not provide the tight temporal control of target inactivation achieved by small molecule inhibitors. On the other hand, development of highly specific inhibitors is challenging and careful design of control compounds is required to validate inhibitors as specific tools to study protease biology1. We believe that chemical and genetic methods need to be combined in order to obtain a comprehensive understanding of protease function.

We will use a multidisciplinary approach combining and comparing genetics vs chemical biology approaches to determine the biological function of the clan C serine peptidases and the DDI-1 type retropepsin in P. falciparum. To achieve this goal we will pursue the following specific aims

AIM1: Determination of Protease Phenotype Through Implementation of a Novel Conditional Knockout System.

AIM2: Development of Chemical Tools to Inhibit and Monitor Protease Activity.

AIM3: Identification of Endogenous Cellular Protease Substrates through quantitative proteomic.

Overall, the multidisciplinary approach presented here will combine the Crick Institute long standing experience in the genetic manipulation of P. falciparum, with GSK's expertise and capabilities in the identification of tool compounds, and Dr Deu's experience in developing