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- **************************************************
- * ER lumen protein retaining receptor signatures *
- **************************************************
-
- Proteins that reside in the lumen of the endoplasmic reticulum (ER) contain a
- C-terminal tetrapeptide (generally K-D-E-L or H-D-E-L) that serves as a signal
- for their retrieval (retrograde transport) from subsequent compartments of the
- secretory pathway. The signal is recognized by a receptor molecule that is
- believed to cycle between the cis side of the Golgi apparatus and the ER [1].
- This protein is known as the ER lumen protein retaining receptor or also as
- the 'KDEL receptor'. It has been characterized in a variety of species,
- including fungi (gene ERD2), plants, Plasmodium, Drosophila and mammals. In
- mammals two highly related forms of the receptor are known.
-
- Structurally, the receptor is a protein of about 220 residues that seems to
- contain seven transmembrane regions [2]. The N-terminal part (3 residues) is
- oriented toward the lumen while the C-terminal tail (about 12 residues) is
- cytoplasmic. There are three lumenal and three cytoplasmic loops.
-
- We developed two signature patterns for these receptors. The first pattern
- corresponds to the C-terminal half of the first cytoplasmic loop as well as
- most of the second transmembrane domain. The second pattern is a perfectly
- conserved decapeptide that corresponds to the central part of the fifth
- transmembrane domain.
-
- -Consensus pattern: G-I-S-x-[KR]-x-Q-x-L-[FY]-x-[LIV](2)-F-x(2)-R-Y
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: L-E-[SA]-V-A-I-L-P-Q-L
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Last update: June 1994 / First entry.
-
- [ 1] Pelham H.R.B.
- Curr. Opin. Cell. Biol. 3:585-591(1991).
- [ 2] Townsley F.M., Wilson D.W., Pelham H.R.B.
- EMBO J. 12:2821-2829(1993).
-