DFG – Deutsche Forschungsgemeinschaft (German Research Foundation)

About

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End of March 2022, the Senate of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) established the Priority Programme “Code𝛘 – Chitin, chitosan and chito-oligosaccharides and their interaction with proteins of the extracellular matrix and cellular signaling” (SPP 2416)”. This programme is designed to run for six years, and the present call invites proposals from researchers working in this field to join for the first three-years funding period.

Aims and Scope of the Programme

Chitin and chitosans (C/CS) are among the most abundant and versatile polymers in nature, occurring as structural components in numerous types of extracellular matrices (ECM), such as the arthropod cuticles, hydrogel-like peritrophic matrices, or fungal cell walls. The structural tenets underlying the immense range of different physicomechanical properties covered by these ECM are currently unknown. Equally, C/CS biosynthesis, assembly and degradation during development, differentiation and morphogenesis as well as their interactions with other cellular components and their involvement in the communication between organisms are poorly understood. Based on emerging new evidence, we strongly believe that the molecular fine structure of C/CS (i.e. degree of polymerisation, degree and pattern of acetylation) and their interactions with different types of C/CS binding proteins (CBP) and C/CS modifying enzymes (CME) contribute to define the ECM properties.

Aims and Scope of the Programme

Chitin and chitosans (C/CS) are among the most abundant and versatile polymers in nature, occurring as structural components in numerous types of extracellular matrices (ECM), such as the arthropod cuticles, hydrogel-like peritrophic matrices, or fungal cell walls. The structural tenets underlying the immense range of different physicomechanical properties covered by these ECM are currently unknown. Equally, C/CS biosynthesis, assembly and degradation during development, differentiation and morphogenesis as well as their interactions with other cellular components and their involvement in the communication between organisms are poorly understood. Based on emerging new evidence, we strongly believe that the molecular fine structure of C/CS (i.e. degree of polymerisation, degree and pattern of acetylation) and their interactions with different types of C/CS binding proteins (CBP) and C/CS modifying enzymes (CME) contribute to define the ECM properties.

In addition, C/CS binding receptors (CBR) of human, animal and plant immune systems trigger defence reactions upon perception of enzymatically produced chito-oligosaccharides (COS). Thus, we hypothesize that the fine-structure of C/CS and COS harbours a code, which we term “Code 𝛘” (the Greek letter “chi” stands for chito), that is “written”, “enacted”, and “interpreted” by a large variety of C/CS binding and modifying proteins in organisms that produce these polymers, as well as C/CS degrading enzymes and binding receptors in environmental hosts that perceive C/CS containing organisms. The Priority Programme aims to decrypt Code 𝛘 and to understand the molecular and biophysical principles of C/CS function in nature.

Find out more about:
Methods
Publications

In addition, C/CS binding receptors (CBR) of human, animal and plant immune systems trigger defence reactions upon perception of enzymatically produced chito-oligosaccharides (COS). Thus, we hypothesize that the fine-structure of C/CS and COS harbours a code, which we term “Code 𝛘” (the Greek letter “chi” stands for chito), that is “written”, “enacted”, and “interpreted” by a large variety of C/CS binding and modifying proteins in organisms that produce these polymers, as well as C/CS degrading enzymes and binding receptors in environmental hosts that perceive C/CS containing organisms. The Priority Programme aims to decrypt Code 𝛘 and to understand the molecular and biophysical principles of C/CS function in nature.

Find out more about:
Methods
Publications
Chitin binding site in TLR-2
Close-up view on the chito-oligosaccharide binding site of Toll-like receptor 2
Human TLR-2 binding a chito-oligosaccharide
Structural model of Toll-like receptor 2 in complex with a chito-oligosaccharide
Human TLR-2 binding a chito-oligosaccharide
Sliced view on the chito-oligosaccharide binding site of Toll-like receptor 2
Full length human TLR-2
Ribbon model of human Toll-like receptor 2
Structure of a chitosan oligomer
Molecular dynamic simulations and NMR analysis of chitosan oligomers suggest particular intramolecular interactions.
Structural glycan imaging
Single molecule imaging of a synthetic glycan obtained by ESI-STM
Cuticle of a locust leg
Fluorescence resulting from resilin/dityrosine in the cutcicle from Schistocerca legs
Yeast cell wall
Calcofluor white staining of budding yeast cells
Cryo-EM structure of PsChs1
Cryo-EM structure of the chitin synthase 1 dimer from Phytophthora sojae (Chen et al., 2022, Nature, https://doi.org/10.1038/s41586-022-05244-5
Peritrophic Matrix
The peritrophic matrix is stained with a fluorescent chitin binding domain (red), the gut content contains FITC-dextran particles (green) and the midgut epithelial nuclei are stained with DAPI (blue)

Programme Committee

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Coordinator: Prof. Dr. Hans Merzendorfer, Dept. of Chemistry-Biology, University of Siegen

Dr. Martina Delbianco

Max-Planck-Institute of Colloids and Interfaces, Potsdam
Dept. of Biomolecular Systems, Carbohydrate Materials

Prof. Dr. Hans Merzendorfer

University of Siegen, Siegen
Dept. of Chemistry-Biology, Molecular Biology

Prof. Dr. Bruno Moerschbacher

University of MĂŒnster, MĂŒnster
Institute of Biology and Biotechnology of Plants, Molecular Phytopathology

Prof. Alexander Weber, Ph.D.

Eberhard Karls University, TĂŒbingen
Dept. of Immunology, Innate Immunity

Prof. Dr. Yael Politi

Technical University Dresden, Dresden
B CUBE – Center for Molecular Bioengineering

Extended Board

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Prof. Dr. Bernard Moussian

Eberhard Karls University, TĂŒbingen
Faculty of Science

Dr. rer. nat. Linus Stegbauer

Institute of Interfacial Process Engineering and Plasma Technology IGVP, University of Stuttgart /// Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB

News

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New DFG Priority Programme

Die Deutsche Forschungsgemeinschaft (DFG) richtet ab 2023 acht neue Schwerpunktprogramme ein. Einer dieser ĂŒberregionalen und interdisziplinĂ€ren Forschungs-VerbĂŒnde wird von Prof.…
News Archive

Projects

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In this area, we will provide information on the participating projects funded in the scope of this priority programme.

Biotechnologically produced chitosans behave different

In a recent article published in Nature Communication it was demonstrated that biotech chitosans with specific acetylation patterns possess different physicochemical properties and biological activities compared to conventional technical chitosans…
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New DFG Priority Programme

Die Deutsche Forschungsgemeinschaft (DFG) richtet ab 2023 acht neue Schwerpunktprogramme ein. Einer dieser ĂŒberregionalen und interdisziplinĂ€ren Forschungs-VerbĂŒnde wird von Prof. Dr. Hans Merzendorfer vom Institut fĂŒr Biologie der UniversitĂ€t Siegen…
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