The present invention relates to various uses of complementing proteins protein fragments to discover chemical compounds or drugs interfering with protein translocation/redistribution and/or protein interactions. The invention takes advantage of the fact that many interacting proteins reside in separate and distinct locations prior to the activation of the signaling pathways in which they play their part. The invention also takes advantage of interaction domains (FRBP, FKBP12) that can be induced to interact. Specifically disclosed are GFP (EGFP, F64L mutated EYFP) complementation.