In response to harmful environmental stresses, such as heat and viral infection, organisms synthesize proteins called stress proteins or heat shock proteins. Stress proteins may either protect organisms from the effects of stress or aid organisms during the recovery from stress. Although stress proteins are induced in response to stress, some stress proteins are constitutively expressed. This suggests that stress proteins also participate in normal cellular activities. Stress proteins may play a role in development, signal transduction, receptor- mediated endocytosis, and protein translocation. The ability of stress proteins to associate with other proteins suggests that they may mediate protein-protein interactions and facilitate protein folding and assembly. Preliminary evidence presented in this proposal suggests that a cytosolic factor facilitates the dissociation of complexes between cytosolic 70K stress proteins and other proteins. During the proposed research I will purify and characterize this factor. The isolation and study of the dissociation factor will provide insight into the molecular events leading to proper folding and assembly of proteins in vivo.
