LuMPIS: Luciferase-Based MBP-Pull-Down Protein Interaction Screening System

Analyzing the putative interaction partners of an individual protein is one approach to elucidate its function. In the LuMPIS protocol, bait and prey proteins are expressed with N-terminal maltose binding protein (MBP)- and eGFP-luciferase (eGFP-luc) tags, respectively. Positive protein–protein interactions (PPIs) can be detected after pull-down of the MBP-tagged prey protein using amylose beads followed by the bioluminescence detection of the bound eGFP-luc-tagged bait protein. The LuMPIS technology offers the following advantages: the PPIs are detected in the mammalian cell context, the use of two long protein tags (i.e., MBP and eGFP-luc) increases the expression levels of genes whose gene expression levels are known to be frequently impaired, the use of amylose beads for pull-down is much more economic as compared to sepharose beads in combination with monoclonal antibodies and finally, the use of an eGFP-luc-tag enables the qualitative control of transfection efficiencies by fluorescence microscopy prior to starting the assay.