Aggregation of the TAR DNA-binding protein (TDP-43) is associated with neurodegenerative disorders such
as frontotemporal degeneration (FTD) and amyotrophic lateral sclerosis (ALS). Any strategy that alters TDP-43
aggregation, function and cellular toxicity may form the basis of potent novel ALS therapies. A major regulator
of protein folding and aggregation in cells is the Hsp70 molecular chaperone. Research has primarily focused
on how Hsp70 function specificity arises through regulation of a) expression of Hsp70, b) isoform differences in
the Hsp70 protein family and c) the variety of co-chaperone proteins that bind to the Hsp70 molecule. Despite
the proteomic identification of over seventy phosphorylation sites on both yeast and mammalian Hsp70, the
biological function of most of these sites remains unknown.
In this proposal, we intend to investigate the connection between post-translational modification (PTM) of
Hsp70 and TDP-43 function. In particular, we will determine how chaperone PTMs are altered in response to the
presence of TDP-43 in mammalian and yeast cells and how the modification of these PTMs impacts TDP-43
toxicity. Finally, we intend to use cross-linking mass spectrometry to analyze the interaction between Hsp70 and
TDP-43 with a focus on the interaction surface between these two proteins. This information will provide ket
preliminary data for larger studies that determine the mechanisms regulating these PTMs and their specific effect
on TDP-43.