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Prof. Franco Falcone

Franco Falcone

Prof. Dr. Franco Falcone
Department of Parasitology
BFS - Biomedical Research Center Seltersberg
Justus Liebig University Giessen
Schubertstraße 81
35392 Giessen
Tel.: +49 641 99 38030

  

Curriculum Vitae

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Project Description

Schistosoma mansoni mitogen-activated protein kinases as new targets for chemotherapy of schistosomiasis

Background:  Protein kinase (PK) proteins are well-characterized cell-signaling molecules that play an important role in Schistosoma mansoni biology. Approximately 2% of its predicted proteome corresponds to PKs, and some of them are thought to be essential for the parasite's life cycle. Recent studies have employed RNAi to help elucidate the role of several mitogen-activated protein kinases (MAPKs) in the parasite.1 For instance, c-Jun N-terminal kinase (SmJNK)2 is a key regulator of parasite maturation and survival. The knockdown of SmJNK in schistosomula significantly increased the parasite's mortality, and the recovered worms showed considerable morphological defects, especially in the tegument.3 When the same strategy was used for the knockdown of extracellular signal-regulated kinases (SmERK1 and 2), low egg numbers were recovered from infected animals, and adult female worms presented severe alterations in the reproductive system.3 More recently, Smp38 knockdown in schistosomula by RNAi was found to affect parasite survival and development, with low egg output and damaged tegument in adult worms and undeveloped female ovaries. Additionally, transcriptional analysis after Smp38 knockdown revealed that this kinase is important for the regulation of key signaling processes in the parasite such as homeostasis and antioxidant defense.4

 

Specific Goals: Considering the high relevance of protein kinases, especially in the drug discovery process, we aim to use MAPKs as targets for drug discovery and development against schistosomiasis. Based on recent elucidations concerning the role of S. mansoni MAP kinases, we are now aiming for 1) structural resolution (crystallography) and 2) computer-aided drug design for in silico and in vitro screening of kinase-targeted compounds using our recently developed kinase fluorescence depolarization screening assay.5 Lead candidates will also be tested ex vivo on parasites and in vivo. Currently, there are four ongoing collaborations: two within the DRUID consortium (Peter Czermak/Denise Salzig, THM Giessen, and Christoph Grevelding, JLU Giessen), and two with external international collaborators (Marina Mourao, Fiocruz Belo Horizonte, Brazil and Atomwise in San Francisco, USA), for achieving the aforementioned goals, with more collaborations planned in the future.

 

References: 1. Andrade et al., 2011 (BMC Genomics) [pmid: 21548963]; 2. Gava et al. [pmid : 31681440]*; 3. Andrade et al., 2014 (Plos NTD) [pmid: 24945272]; 4. Avelar et al., 2019 (Frontiers in Immunology) [pmid: 30733716]; 5. Moreira et al., 2019 (ACS Omega) [10.3389/fimmu.2019.00021]*

 

 

Fig 1. Schematic representation of the fluorescence polarization assay using BODIPY-labeled ATP analogue as a probe for screening kinase type-1 inhibitors. The shift in fluorescence polarization indicates whether the probe is bound to the target kinase or has been displaced by a kinase inhibitor compound. PKA is protein kinase A.

 

 

 

 

 

 Fig 2. Use of the ATP derivative, ATP-y-S BODIPY FL in a fluorescence polarization assay. (A) Structure of the probe. (B) Fluorescence polarization value in response to increasing amounts of the probe in three different conditions regarding the presence or absence of the detergent (Tween-20) in the buffer.

 

 

Fig 3. Competition for the nucleotide binding site of PKA. (A) Structure of H7 inhibitor, a known kinase inhibitor. (B) Blocking of the binding between the probe and PKA by H7 inhibitor.