Molecular mechanism of the Hsp70 Chaperone network

• Applicant: Professor Dr. Matthias Peter Mayer
• Subject Area: Biochemistry
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 462625623

The molecular chaperones of the 70 kDa heat shock protein (Hsp70) family are central components of the cellular protein quality surveillance network. To no other class of chaperones a comparable diversity of functions have been attributed. Through their protein folding functions Hsp70s influence many regulatory signaling processes and cellular control circuits, impacting cellular homeostasis, proliferation, differentiation and programmed cell death. Thereby Hsp70s are involved in many pathophysiological processes like cancer, neurodegeneration, inflammation and infections with many types of pathogens. The basis for this wide variety of functions is the tweezer-like interaction of Hsp70s’ substrate binding domain with short degenerative amino acid sequence motifs in client proteins that is regulated by an intricate allosteric mechanism by Hsp70s’ nucleotide binding domain. Hsp70s are targeted to their clients by cochaperones of the J-domain protein (JDP) family and the life-time of the Hsp70-client complex is regulated by nucleotide exchange factors (NEFs).The overarching goal of this research projects is to further our molecular understanding of the Hsp70 machinery, not only as a tripartite core machine of a single Hsp70, a single JDP and a single NEF, but in its oligomeric states and as a complex network of multiple Hsp70s, JDPs and NEFs that might cooperate or compete with each other. The elucidation of the intricacies of the cellular Hsp70 system and its regulation will lay a better foundation for developing drugs that enhance or inhibit the activity of this machinery possibly in a more specific way to fight diseases like cancer and neurodegeneration and, potentially, infections. The specific aims are (1) to develop a sensor for high throughput detection of JDP-targeted interaction of Hsp70s with amino acid sequence motifs; (2) to elucidate the functional implications of the oligomerization within the Hsp70 system; and (3) to map the interconnectivity of the Hsp70-JDP network of the nuclear-cytoplasmic compartment of human cells. To achieve these goals we will employ genetic, biochemical, and cell biological methods, including mutagenesis, luminescence-based interaction screens, fluorescence resonance energy transfer, and fluorescence life-time imaging.

• DFG Programme: Research Grants