The invention provides methods of screening to identify compounds that modulate the ability of a protein to translocate to the mitochondria when a cell is subjected to cellular stress. Such compounds can be useful to modulate the level of apoptosis in a cell. For example, compounds identified according to the methods described herein can be used to treat disorders characterized by excessive apoptosis, e.g., a neurological disorder, or insufficient apoptosis, e.g., cancer.