This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie COFUND grant agreement No 665735.

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22: Bio4Med - Palmitoylated proteins of plasma membrane domains as regulators of TLR4 signaling

prof. Katarzyna Kwiatkowska
Foreign partner:
Prof. Vaclav Horejsi, Academy of Sciences of the Czech Republic, Prague, Czech Republic
Activation of macrophage Toll like receptor 4 (TLR4) by bacterial lipopolysaccharide (LPS) induces pro-inflammatory responses directed at eradicating the bacteria. However, excessive host responses to LPS can lead to sepsis. It has been recognized that TLR4 activation requires its association with plasma membrane domains, both sphingolipid-cholesterol-based rafts and tetraspanin-enriched microdomains. As numerous raft-associated protein are palmitoylated, we hypothesize that this reversal posttranslational acylation of proteins can be a key factor modulating TLR4 signaling.
The aim of this project is to reveal the role of selected palmitoylated proteins in the signaling of TLR4 in macrophages. We will focus on palmitoylated adaptor proteins which are anchored in lipid rafts and tetraspanin-enriched domains and recruit proteins of regulatory functions in signaling pathways. To reveal the dynamics of palmitoylation of selected proteins during stimulation of cells with LPS “click” chemistry will be applied. We plan to demonstrate the involvement of adaptor proteins in the organization of TLR4 signaling complexes and in generation of pro-inflammatory signals. For this purpose we will silence expression of appropriate genes and examine how it will affect activation of MAP kinases, NFκB and IRF3, the main effectors of TLR4. Production of pro-inflammatory cytokines will be also assessed. Furthermore, we shall establish whether an interference with palmitoylation of these proteins will affect the assembly of TLR4 signaling complexes and pro-inflammatory responses induced by LPS. Confocal microscopy studies and biochemical analysis based on fractionation of detergent cell lysates will be performed to detected distribution of studied proteins in cells and to examine their colocalization with TLR4 and CD14. We posit that palmitoylation of selected proteins is a prerequisite for their involvement as regulators in TLR4 signaling.
Master of Science degree in molecular biology, biochemistry, biology Interest in cell biology and immunology Motivation for scientific research judged by references and internships at research institutes Knowledge of English Candidates must not have resided or carried out their main activity (work, studies, etc.) in Poland for more than 12 months in the past 3 years.