PROTstretch - Dynamic structure of a nanomachine involved in proteome quality control: a combined NMR/SAXS/SANS study of the PAN unfoldase

• Applicant: Professorin Dr. Teresa Carlomagno
• Subject Area: Structural Biology ; Biochemistry
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 283154463

The aim of the p project is to gain insight into the molecular mode of action of an important class of biomacromolecular machines, the so-called AAA ATPase unfolding machines. A healthy proteome, i.e. the ensemble of proteins present at a given point in time in a cell, is essential for the correct functioning of any organism. Numerous regulatory mechanisms exist at the gene expression and post-translational levels that control the amount, specificity and activity of proteins, in response to variable internal and external environments. In living cells one of these mechanisms consists in trapping and degrading disabled proteins. This function is critical, since abnormally folded proteins have a tendency to aggregate and can provoke irreversible damages to the cell. The central challenge for specific protein degradation is to complete the unfolding of proteins that display an abnormal conformational state or that are no longer needed. This task is accomplished by different classes of AAA ATPases unfolding machines (unfoldases) that prepare the proteins for degradation via the proteasomes. Because of their pivotal position in the protein degradation pathway, unfoldases are currently discussed as potential lead compounds for therapeutic intervention. In humans, an altered function in defective protein elimination can cause a number of destructive diseases, such as Alzheimer or Huntington, and is also at the basis of infective diseases, such as prions. Neurodegenerative diseases, in particular, are more likely to occur with age, which constitutes a considerable health issue for the aging world population. In this context, understanding in depth the mode of action of unfoldase machineries represents a major goal in biomedicine. Classical structural biology techniques, such as crystallography, are limiting when applied to such complex dynamic and oligomeric systems and cannot provide a full understanding of their mode of action. Here we address these questions using a powerful combination of structural biology techniques in solution: small-angle X-ray (SAXS) and neutron (SANS) scattering as well as nuclear magnetic resonance spectroscopy (NMR). We propose to apply this combination of techniques to the PAN system using GFP as a substrate.

• DFG Programme: Research Grants
• International Connection: France
• Partner Organisation: Agence Nationale de la Recherche / The French National Research Agency
• Cooperation Partner: Dr. Frank Gabel