COMPOSITIONS, SYSTEMS, AND METHODS FOR MEASURING PROTEIN SECRETION AT A SINGLE-CELL LEVEL

摘要

Compositions, systems and methods for measuring secretion of a protein-of- interest that include trap proteins and reporter proteins for secretion by a cell. Each trap protein comprises a binding partner, a first fluorescent label, and an outer leaflet anchor to anchor the trap protein to the outer leaflet of the cell to form a secretory trap. Each reporter protein comprises a protein-of-interest, a second fluorescent label, and an optogenetic tool to, in a dark conformation, reversibly heterodimerize with the binding partner, and, in a lit conformation, photo-release the binding partner. Upon secretion of the trap and reporter proteins by the cell, optogenetic tools in the dark conformation, reversibly heterodimerizes with binding partners to reversibly sequester secreting reporter proteins at a secretory trap, and in the lit conformation photo-release the binding-partner of sequestered reporter proteins to facilitate measurement of the secretion of protein-of interest comprised by the reporter proteins.