Phosphoproteomanalyse von Phagosomenproteinen

• Applicant: Dr. Matthias Trost
• Subject Area: Immunology
• Term: from 2005 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5452648

Phagocytosis is the process used by a variety of cells to internalizelarge (bigger as 0.5 µm) particles such as microbesand apoptotic cells. The internalization of these particles resultsin membrane-bound organelles, called phagosomes. In cellsof the immune system such as macrophages, phagosomes fuse withendocytic organelles to form phagolysomes where pathogens arekilled and degraded into peptides that can be presented at thecell surface on MHC class 11 molecules. Therefore, phagocytosisplays important roles in innate and adaptive immunity. Manypathogens are able to inhibit the formation of phagolysomes andsurvive and replicate within macrophages. The molecular mechanismsinvolved in phagolysosome biogenesis and those used bypathogens to subvert the functional properties of phagosomesare still poorly understood.The aim of this project is to study how the modulation of thephagosome proteome confers novel functional properties to thisorganelle. Phagosomes isolated from macrophages treated or notwith interferon-µ, a cytokine that increases the anti-microbialproperties of phagosomes, will be analyzed using tandem massspectrometry. An emphasis will be directed to the identificationof phosphorylated proteins and the characterization oftheir phosphorylated sites. Identified target proteins will befurther examined by cell biological methods for their relevancein phagosomal maturation, antimicrobial activity and immunity.

• DFG Programme: Research Fellowships