Protein-protein interaction assessed by detecting localized coiled coil subunits

A method of detecting protein-protein interaction between a first interacting protein and a second interacting protein, comprising the steps of:

• expressing a first monomer in the cell, wherein the first monomer is a fusion protein, wherein the fusion protein comprises:
• a first coiled coil subunit that will spontaneously form a homo-oligomer with other coiled coil subunits of the same sequence;
• and the first interacting protein;
• expressing a second monomer in the cell, wherein the second monomer is a fusion protein, wherein the fusion protein comprises:
• a second coiled coil subunit that will spontaneously form a homo-oligomer with other coiled coil subunits of the same sequence;
• and the second interacting protein;
• wherein the first and second coiled coil subunits comprise different sequences;
• wherein the first monomer, the second monomer, or both the first and second monomers further comprises one or more reporter moieties;
• and
• by methods of detecting the one or more reporter moieties, observing the cell for the formation of localized punctae comprising phase-shifted droplets of concentrated aggregates of homo-oligomers of the first monomer and homo-oligomers of the second monomer, wherein the formation of the aggregations of punctae is driven by the interaction of the first interacting protein and the second interacting protein.