A protein that normally would have a KDEL sequence is mutated so that it no longer has the signal. What will be the result? the protein will most likely be secreted the protein will no longer be glycosylated the protein no longer exits the ER the protein will be translocated out of the ER and degraded by a proteasome the protein will no longer be targeted to lysosomes How come KDEL receptor proteins can escape the ER membrane but then can be trafficked back? KDEL sequences target ER lumen proteins to the Golgi KDEL receptors bind proteins with the KDEL sequence in the ER lumen KDEL receptors release proteins with ER retention sequences in the Golgi lumen binding of a protein with a KDEL sequence to a KDEL receptor causes a conformational change in the KDEL receptor that allows its packaging into retrieval vesicle. When the KDEL receptor releases its cargo in the ER lumen, the protein returns to its unbound conformation. .