KDEL (amino acid)
Encyclopedia
KDEL is a sequence in the amino acid
structure of a protein
which keeps it from secreting from the endoplasmic reticulum
(ER). It also targets proteins from other locations (such as the cytoplasm
) to the ER. Proteins can only leave the ER after this sequence has been cleaved off.
The KDEL sequence is responsible for retrieval of ER luminal proteins from the Golgi apparatus
. The abbreviation KDEL is formed by the corresponding letters to each amino acid. This letter system was defined by the IUPAC and IUBMB in 1983, and is as follows:
Therefore, the sequence in three letter code is: Lys
-Asp
-Glu
-Leu
.
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
structure of a protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
which keeps it from secreting from the endoplasmic reticulum
Endoplasmic reticulum
The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae...
(ER). It also targets proteins from other locations (such as the cytoplasm
Cytoplasm
The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...
) to the ER. Proteins can only leave the ER after this sequence has been cleaved off.
The KDEL sequence is responsible for retrieval of ER luminal proteins from the Golgi apparatus
Golgi apparatus
The Golgi apparatus is an organelle found in most eukaryotic cells. It was identified in 1898 by the Italian physician Camillo Golgi, after whom the Golgi apparatus is named....
. The abbreviation KDEL is formed by the corresponding letters to each amino acid. This letter system was defined by the IUPAC and IUBMB in 1983, and is as follows:
- K—LysineLysineLysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....
- D—Aspartic acidAspartic acidAspartic acid is an α-amino acid with the chemical formula HOOCCHCH2COOH. The carboxylate anion, salt, or ester of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins...
- E—Glutamic acidGlutamic acidGlutamic acid is one of the 20 proteinogenic amino acids, and its codons are GAA and GAG. It is a non-essential amino acid. The carboxylate anions and salts of glutamic acid are known as glutamates...
- L—LeucineLeucineLeucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
Therefore, the sequence in three letter code is: Lys
Lysine
Lysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....
-Asp
Aspartic acid
Aspartic acid is an α-amino acid with the chemical formula HOOCCHCH2COOH. The carboxylate anion, salt, or ester of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins...
-Glu
Glutamic acid
Glutamic acid is one of the 20 proteinogenic amino acids, and its codons are GAA and GAG. It is a non-essential amino acid. The carboxylate anions and salts of glutamic acid are known as glutamates...
-Leu
Leucine
Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
.
See also
- ER retentionER retentionER retention refers to proteins that are retained in the endoplasmic reticulum, or ER, after folding; these are known as ER resident proteins....
- Endoplasmic reticulum protein retention receptors
- KDELR1KDELR1KDEL endoplasmic reticulum protein retention receptor 1, also known as KDELR1, is a protein which in humans is encoded by the KDELR1 gene.- Function :...
- KDELR2KDELR2ER lumen protein retaining receptor 2 is a protein that in humans is encoded by the KDELR2 gene.Retention of resident soluble proteins in the lumen of the endoplasmic reticulum is achieved in both yeast and animal cells by their continual retrieval from the cis-Golgi, or a pre-Golgi compartment...
- KDELR3KDELR3ER lumen protein retaining receptor 3 is a protein that in humans is encoded by the KDELR3 gene.Retention of resident soluble proteins in the lumen of the endoplasmic reticulum is achieved in both yeast and animal cells by their continual retrieval from the cis-Golgi, or a pre-Golgi compartment...
- KDELR1