Poster Presentation The 42nd Lorne Conference on Protein Structure and Function 2017

Towards a general classification of chaperone activities (#140)

Nichole Giles 1 , Tobias Rosenkranz 1 , Till Boecking 1 , Emma Sierecki 1 , Yann Gambin 1
  1. Single Molecule Sciences, EMBL Australia Node, UNSW, Sydney, Kensington, NSW, Australia

Molecular chaperones are key regulators of protein folding and proteostasis. As such, they are becoming valuable therapeutic targets in neurodegenerative diseases caused by protein misfolding and aggregation or in cancer where over-expression of chaperones facilitates tumourgenesis. Chaperones are currently differentiated based on their molecular weight (Hsp90, Hsp70, Hsp60 small Hsp (HSPB) and large Hsp (HSPH)). While their role is slowly being understood, the activities of most chaperones and the differences within the families are ill defined. Here, we aim to classify the HSP branch of human chaperones based on the molecular mechanisms. As chaperones do not function alone, the first goal is to map their potential networks. Proteins will be expressed using cell-free expression system and their propensity to self-associate and form hetero-complexes will be investigated using AlphaScreen assay. Positive interactions will be further analysed to determine the stoichiometry using confocal microscopy. These data will then be analysed for their cell type and cellular localization.  The chaperones will be categorized in 3 categories: (i) type I: ablity to refold misfolded protein to native state (ii) type II: degradation of aggregates back to monomeric native or misfolded form and (iii) type III: promote aggregation of misfolded proteins. Here, aggregation, luminescence or FRET assays will be used to establish the model systems to evaluate the chaperones.