The sequence Lys-Asp-Glu-Leu (KDEL) serves to retain proteins in the ER by
A) preventing their packaging into vesicles destined for the Golgi.
B) binding to receptors within the membranes of the ERGIC and Golgi, which retain them or return them to the ER.
C) binding the SRP receptor in the ER membrane.
D) associating with the lipids in the ER membrane.

Question

Quizplus · Accepted Answer

The KDEL sequence binds to receptors within the membranes of the ERGIC and Golgi, which retain them or return them to the ER. This is known as the KDEL retrieval system.

The Sequence Lys-Asp-Glu-Leu (KDEL) Serves to Retain Proteins in the ER