SPP 2416:  CodeChi - Chitin, chitosan and chito-oligosaccharides and their interaction with proteins of the extracellular matrix and cellular signaling

• Subject Area: Biology ; Agriculture, Forestry and Veterinary Medicine ; Chemistry ; Materials Science and Engineering ; Medicine
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 500927941

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. The structural tenets underlying their immense range of different physicomechanical properties are currently unknown. Equally, C/CS biosynthesis, assembly and degradation as well as their interactions with 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 (e.g. degree of polymerization; the degree and pattern of acetylation), contributes to define the properties of C/CS-containing biological matrices and functional materials. In addition, C/CS-binding receptors of human, animal and plant immune systems trigger defense reactions upon perception of C/CS oligomers (COS) produced by the action of C/CS-degrading enzymes. Thus, we hypothesize that the fine-structure of C/CS and COS harbors a code, which we term “CodeChi”, that is “written”, “enacted” and “interpreted” by a large variety of C/CS-binding and C/CS-modifying proteins in organisms that produce these polymers, as well as C/CS-degrading enzymes and C/CS-binding receptors in environmental hosts that perceive C/CS-containing organisms. The Priority Programme 2416 aims to decrypt “CodeChi”, to understand the molecular and biophysical principles of C/CS functions in nature and to utilize this knowledge for the fabrication of functional materials. The coordination project accounts responsible for achieving the overall goals of the SPP2416 by ensuring effective collaboration between the different disciplines and providing the necessary infrastructure for a successful work. It will be the central interface for administration and coordination of the research consortium. The coordination project will establish and maintain multiple platforms for scientific exchange and networking activities, and pursue measures to ensure public and international visibility. It will particularly support young investigators in their early careers, apply instruments for equal opportunity, female and family-friendly promoting policies. Finally, the coordination projects will govern three service projects that provide expertise and capability in: 1) the synthesis and structural analysis of chemically defined chito-oligosaccharides; 2) production of specific chitins and chitosans and quantitative analysis of the degree of polymerization and fraction of acetylation; 3) determination of kinetic parameters for the binding of proteins to crystalline chitin nanofibers and chito-oligomers. The coordination office will be located at the Department of Chemistry-Biology, School of Natural Science and Technology, University of Siegen, and will support the coordinator in his work.

• DFG Programme: Priority Programmes
• International Connection: France

Projects

• Biogenesis of chitin matrices across scales in yeast and insect (Applicants Bertinetti, Ph.D., Luca ;  Mattei, Simone )
• Chitin oligosaccharide recognition by human chitinase-like proteins: Deciphering CodeChi at the atomistic level and its impact on cellular signaling (Applicants Cramer, Jonathan ;  Gohlke, Holger )
• Coordination Funds (Applicant Merzendorfer, Hans )
• Deciphering the molecular pathways and codeχ-specificity of stomatal closure – from model plants to crops (Applicant Böhmer, Maik )
• Decoding the chitin signatures generated by Xylella fastidiosa (Applicant Robatzek, Silke )
• From synthetic chitin oligomers to well-defined chitin-based materials (Applicant Delbianco, Martina )
• Mesostructured composite chitosan membranes for the reconstruction of Corneal Tissue (Applicants Geerling, Gerd ;  Lang, Gregor )
• Principles of extra- and intracellular chitin perception by mammalian pattern recognition receptors (Applicant Weber, Ph.D., Alexander )
• Role of the chito-structural code in controlling inflammatory and tissue regenerative processes in the frame of biomedical applications (Applicants Gorzelanny, Christian ;  Osorio-Madrazo, Anayancy )
• Single Molecule Visualization of Chitin/Chitosan Structures and their Protein Interactions (Applicant Anggara, Kelvin )
• Structure-function relationships of partially acetylated chitosans – ChitoCode (Applicant Moerschbacher, Bruno )
• The impact of CodeChi on the physicochemical properties and 3D organization of the peritrophic matrix from the model pest beetle Tribolium castaneum (Applicant Merzendorfer, Hans )
• The role of CodeChi and chitin-associated proteins in the cell-cell interactions of free-living protists (Applicant Hess, Sebastian )
• Timing of chitin/chitosan matrix assembly in insects (Applicants Gorb, Stanislav N. ;  Lehmann, Fritz-Olaf ;  Moussian, Bernard )
• Utilizing Chitosan-RNA-protein microgels as delivery platform for RNA-mediated gene modulation in plants (Applicants Koch, Aline ;  Pich, Andrij )

• Spokesperson: Professor Dr. Hans Merzendorfer