The invention provides methods and compositions for modulating the expression,processing, post-translational modification, and/or activity of XBP-1 protein,or a protein in a signal transduction pathway involving XBP-1. Exemplary XBP-1activities that can be modulated using the methods and compositions of theinvention include: the Unfolded Protein Response (UPR), plasma celldifferentiation, immunoglobulin production, apoptosis and the production of IL-6. The present invention also pertains to methods for identifying compoundsthat modulate the expression, processing, post-translational modification,and/or activity of XBP-1 protein or a molecule in a signal transductionpathway involving XBP-1.
