Heat Shock Protein 90 (Hsp90) is an essential chaperone that supports the function of a wide range of signaling molecules. Hsp90 binds to a suite of co-chaperone proteins that regulate Hsp90 function through alteration of intrinsic ATPase activity. Several studies have determined Aha1 to be an important co-chaperone whose binding to Hsp90 is modulated by phosphorylation, acetylation and SUMOylation of Hsp90 [1,2]. In this study, we applied quantitative affinity-purification mass spectrometry (AP-MS) proteomics to understand how phosphorylation of hAha1 at Y223 altered global client/co-chaperone interaction . Specifically, we characterized and compared the interactomes of Aha1-Y223F (phospho-mutant form) and Aha1-Y223E (phospho-mimic form). We identified 99 statistically significant interactors of hAha1, a high proportion of which (84%) demonstrated preferential binding to the phospho-mimic form of hAha1.The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository  with the dataset identifier PXD001737.
Wolfgeher, D., Dunn, D. M., Woodford, M. R., Bourboulia, D., Bratslavsky, G., Mollapour, M., … Truman, A. W. (2015). The dynamic interactome of human Aha1 upon Y223 phosphorylation. Data in Brief, 5, 752–755. https://doi.org/10.1016/j.dib.2015.10.028