A TRAP SYSTEM FOR THE ISOLATION OF AMINO-ACID-SEQUENCES INDUCING GPI ANCHOR ADDITION

We designed a trap system to isolate different amino acid sequences wh ich could target proteins to the cell surface via GPI anchor transfer. This selection procedure is based on the insertion of various sequenc es which regenerate a functional GPI anchor signal sequence and theref ore provoke re-expression at the surface of a reporter molecule. Using this trap for cell surface targeting sequences, we could show the imp ortance of the defined elements essential for GPI anchor addition. Suc h a system could be used for an exhaustive analysis of the carboxyl te rminus structural requirements for GPI membrane anchoring.