Structure and Regulation of the Myofibrillar Z-disc Interactome

• Applicant: Professorin Dr. Kristina Djinovic-Carugo
• Subject Area: Structural Biology
• Term: from 2010 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 148688621

Sarcomers, the building units of striated muscles, are composed of highly ordered thick and thin filaments that slide past each other during contraction. One of the functionally most complex sub-compartments of the sarcomere is the Z-disc that forms the lateral boundaries between adjacent sarcomeres. This region plays a central role as the site organizing thick filaments and titin into the molecular machinery that is required for muscle contraction. Apart from its major components – actin filaments, α-actinin and titin, Z-disc comprises a number of other proteins and acts as a platform for an enormously complex and dynamic web of interactions. The aim of the proposed research is to generate novel structural information at the molecular level on selected complexes centered on two essential sarcomeric Z-disc components: α-actinin and filamin C and two adaptors binding partners myopodin, and calsarcin/FATZ/myozenin, that both bind to α-actinin and filamin C and are in parallel being functionally characterized by partner groups (P1, P2, P10). Adaptor proteins play an important role in cytoskeletal assemblies and signalling by physically connecting proteins with distinct functions. We plan to characterize firstly binary interactions and subsequently study ternary and higher complexes in order to generate models about how adaptor proteins bind simultaneously to multiple ligands.We will employ a combination of structural and biophysical methods to characterize these interactions. To complement high and lower structural techniques (crystallography, NMR, small angle X-ray scattering) and well established binding experiments (ITC, SPR), we will use mass spectrometry techniques to characterise the interaction between the partners and inform the lower resolution structural and functional/mutational studies. The structural characterization will be correlated to the in vivo and in vitro functional data generated by the network partners. The research will therefore be performed in close collaboration with cell biology (P1, P2, P10), proteomics (P4), biophysics and structural biology groups of the network (P5, P7, P8, P9), at various levels from the fine design of functional constructs and their functional analysis in vivo and in vitro to the proteomics analysis of the Z-disc interactome.

• DFG Programme: Research Units
• Subproject of: FOR 1352: Structure, Function and Regulation of the Myofibrillar Z-disc Interactome
• International Connection: Austria
• Partner Organisation: Fonds zur Förderung der wissenschaftlichen Forschung (FWF)