My laboratory is interested in the roles of molecular chaperones in regulating signal transduction pathways. In particular, we study the function of the cytosolic chaperone Hsp90, which interacts with a diverse subset of client proteins, ranging from steroid hormone receptors to oncogenic protein kinases such as Her2. Hsp90, along with a number of co-chaperone proteins, interacts with client proteins in an ordered, ATP-dependent pathway that is conserved from yeast to plants to humans. We use a combined genetic and biochemical approach in Saccharomyces cerevisiae to dissect the individual roles of the co-chaperones in this folding pathway. Current work focuses establishing unique functions of the twelve Hsp90 co-chaperones in yeast in order to understand whether clients require the same, or different, sets of cochaperones. Another area of research is to identify mutations in Hsp90 that affect only some clients, such as kinases. Together, these approaches will lead to new understanding of how to selectively inhibit Hsp90 function in order to disrupt the activity of Hsp90-dependent oncogenes without disrupting the function of other Hsp90-dependent cellular proteins.
Kravats AN, Hoskins JR, Reidy M, Johnson JL, Doyle SM, Genest O, Masison DC, Wickner S. (2018) Functional and physical interaction between yeast Hsp90 and Hsp70. PNAS. 10.1073/pnas.1719969115
Cox, MB and Johnson, JL. (2018) Evidence for Hsp90 cochaperones in regulating Hsp90 function and promoting client protein folding. Methods Molecular Biology 2018. 1709:397-422.
Zuehlke AD, Reidy M, Lin C, LaPointe P, Alsomairy S, Lee DJ, Rivera-Marquez GM, Beebe K, Prince T, Lee S, Trepel JB, Xu W, Johnson J, Masison D, Neckers L. (2017) An Hsp90 co-chaperone protein in yeast is functionally replaced by site-specific posttranslational modification in humans. Nat Commun. 2017 May 24;8:15328.
Tenge VR, Zuehlke AD, Shrestha N, and Johnson JL. (2015) The Hsp90 co-chaperones Cpr6, Cpr7 and Cns1 interact with the intact ribosome. Eukaryotic Cell. 14(1):55-63.
Paul A, Garcia YA, Zierer B, Patwardhan C, Gutierrez, O Hildenbrand Z, Harris DC, Balsiger HA, Sivils JC, Johnson JL, Buchner J, Chadli A and Cox MB (2014). The Cochaperone SGTA (Small Glutamine-Rich Tetratricopeptide Repeat-Containing Protein Alpha) Demonstrates Regulatory Specificity for the Androgen, Glucocorticoid and Progesterone Receptors. Journal of Biological Chemistry. 289: 15297-15308.
Tenge, V, Knowles J. and Johnson JL (2014). The ribosomal biogenesis protein Utp21 interacts with Hsp90 and has differing requirements for Hsp90-associated proteins. PLOS One 9(3):e92569.
Zuehlke AD, Wren N, Tenge V and Johnson JL. (2013) Interaction of Hsp90 and the co- chaperone Cpr6 with Ura2, a bifunctional enzyme required for pyrimidine biosynthesis. Journal of Biological Chemistry. 288:27406-27141.