CD98
Encyclopedia
CD98 is a glycoprotein
that is a heterodimer composed of SLC3A2
and SLC7A5
that forms the large neutral amino acid transporter (LAT1). LAT1 is a heterodimeric membrane transport protein that preferentially transports branched-chain (valine
, leucine
, isoleucine
) and aromatic
(tryptophan
, tyrosine
) amino acid
s. LAT is highly expressed in brain capillaries (which form the blood-brain barrier
) relative to other tissues.
A functional LAT1 transporter is composed of two proteins encoded by two distinct genes:
Glycoprotein
Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...
that is a heterodimer composed of SLC3A2
SLC3A2
4F2 cell-surface antigen heavy chain is a protein that in humans is encoded by the SLC3A2 gene.SLC3A2 comprises the light subunit of the large neutral amino acid transporter that is also known as CD98 .- Function :SLC3A2 is a member of the solute carrier family and encodes a cell surface,...
and SLC7A5
SLC7A5
Solute carrier family 7 member 5 also known as large neutral amino acids transporter small subunit 1 is a protein that in humans is encoded by the SLC7A5 gene....
that forms the large neutral amino acid transporter (LAT1). LAT1 is a heterodimeric membrane transport protein that preferentially transports branched-chain (valine
Valine
Valine is an α-amino acid with the chemical formula HO2CCHCH2. L-Valine is one of 20 proteinogenic amino acids. Its codons are GUU, GUC, GUA, and GUG. This essential amino acid is classified as nonpolar...
, leucine
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...
, isoleucine
Isoleucine
Isoleucine is an α-amino acid with the chemical formula HO2CCHCHCH2CH3. It is an essential amino acid, which means that humans cannot synthesize it, so it must be ingested. Its codons are AUU, AUC and AUA....
) and aromatic
Aromatic amino acids
Aromatic amino acids are amino acids that include an aromatic ring.Examples include:* Among 20 standard amino acids: phenylalanine, tryptophan, and tyrosine* Others: thyroxine-See also:* Aromatic L-amino acid decarboxylase...
(tryptophan
Tryptophan
Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
, tyrosine
Tyrosine
Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
) amino acid
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...
s. LAT is highly expressed in brain capillaries (which form the blood-brain barrier
Blood-brain barrier
The blood–brain barrier is a separation of circulating blood and the brain extracellular fluid in the central nervous system . It occurs along all capillaries and consists of tight junctions around the capillaries that do not exist in normal circulation. Endothelial cells restrict the diffusion...
) relative to other tissues.
A functional LAT1 transporter is composed of two proteins encoded by two distinct genes:
- 4F2hc/CD98 heavy subunit protein encoded by the SLC3A2SLC3A24F2 cell-surface antigen heavy chain is a protein that in humans is encoded by the SLC3A2 gene.SLC3A2 comprises the light subunit of the large neutral amino acid transporter that is also known as CD98 .- Function :SLC3A2 is a member of the solute carrier family and encodes a cell surface,...
gene - CD98 light subunit protein encoded by the SLC7A5SLC7A5Solute carrier family 7 member 5 also known as large neutral amino acids transporter small subunit 1 is a protein that in humans is encoded by the SLC7A5 gene....
gene
See also
- Cluster of differentiationCluster of differentiationThe cluster of differentiation is a protocol used for the identification and investigation of cell surface molecules present on white blood cells, providing targets for immunophenotyping of cells...
- Transmembrane proteinTransmembrane proteinA transmembrane protein is a protein that goes from one side of a membrane through to the other side of the membrane. Many TPs function as gateways or "loading docks" to deny or permit the transport of specific substances across the biological membrane, to get into the cell, or out of the cell as...
- Transport proteinTransport proteinA membrane transport protein is a membrane protein involved in the movement of ions, small molecules, or macromolecules, such as another protein across a biological membrane. Transport proteins are integral membrane proteins; that is they exist within and span the membrane across which they...
- Solute carrier familySolute carrier familyThe solute carrier group of membrane transport proteins include over 300 members organized into 51 families. The SLC gene nomenclature system was originally proposed by the Human Genome Organization and is the basis for the official HUGO names of the genes that encode these transporters...