Heterodimeric amino-acid transporter

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Heterodimeric amino-acid transporters are a family of transport proteins that facilitate the transport of certain amino acids across cell membranes. [1] Each transporter comprises a two-protein, a light and heavy, subunit. Transport activity is located in the light subunit.

The following table lists the members of this family:

Transport systemLight subunitHeavy subunitTissue distributionSubstratesAffinitySodium dependenceDisease linkage
LLAT1 (SLC7A5)4F2hc (SLC3A2)kidney, liver, intestine, brain, heart lung, blood–brain barrier large neutral amino acids, thyroid hormones micromolarno
LLAT2 (SLC7A8)4F2hc (SLC3A2)kidney, intestine, brain, liver, muscle, heart, lungsmaller neutral amino acidsmillimolarno
y+Ly+LAT1 (SLC7A7)4F2hc (SLC3A2)kidney, intestine, lung, erythrocytes, leukocyteslarge neutral amino acids, dibasic amino acid exchangemicromolaryes Lysinuric protein intolerance
y+Ly+LAT2 (SLC7A6)4F2hc (SLC3A2)brain, intestine, heart, kidney, lung, liverneutral amino acids, dibasic amino acid exchange, glutamine/arginine exchangemillimolaryes
xcxCT (SLC7A11)4F2hc (SLC3A2)macrophages, liver, kidney, brainglutamine/cystine exchangeno
ascascAT1 (SLC7A10)4F2hc (SLC3A2)brain, lung, small intestine, kidneysmall neutral amino acidsno
b0,+b0,+AT1 (SLC7A9)rBAT (SLC3A1)kidney, intestine, brainneutral/dibasic amino acidsno Cystinuria type I

Related Research Articles

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 and aromatic amino acids. LAT is highly expressed in brain capillaries relative to other tissues.

Excitatory amino acid transporter 4

Excitatory amino-acid transporter 4 (EAAT4) is a protein that in humans is encoded by the SLC1A6 gene.

b(0,+)-type amino acid transporter 1

b(0,+)-type amino acid transporter 1, also known as b(0,+)AT1, is a protein which in humans is encoded by the SLC7A9 gene.

Neutral and basic amino acid transport protein rBAT

Neutral and basic amino acid transport protein rBAT is a protein that in humans is encoded by the SLC3A1 gene.

4F2 cell-surface antigen heavy chain

4F2 cell-surface antigen heavy chain is a protein that in humans is encoded by the SLC3A2 gene.

Proton-coupled amino acid transporter 1

Proton-coupled amino acid transporter 1 is a protein that in humans is encoded by the SLC36A1 gene.

Cystine/glutamate transporter

Cystine/glutamate transporter is an antiporter that in humans is encoded by the SLC7A11 gene.

Sodium-coupled neutral amino acid transporter 2

Sodium-coupled neutral amino acid transporter 2 is a protein that in humans is encoded by the SLC38A2 gene.

Large neutral amino acids transporter small subunit 2

Large neutral amino acids transporter small subunit 2 is a protein that in humans is encoded by the SLC7A8 gene.

An amino acid transporter is a membrane transport protein that transports amino acids. They are mainly of the solute carrier family.

SLC6A14

Sodium- and chloride-dependent neutral and basic amino acid transporter B(0+) (SLC6A14) is a protein that in humans is encoded by the SLC6A14 gene.

SLC20A2

Sodium-dependent phosphate transporter 2 is a protein that in humans is encoded by the SLC20A2 gene.

Large neutral amino acids transporter small subunit 3

Large neutral amino acids transporter small subunit 3 is a protein that in humans is encoded by the SLC43A1 gene.

Large neutral amino acids transporter small subunit 1

Large neutral amino acids transporter small subunit 1, also known as 4F2 light chain, is a protein that in humans is encoded by the SLC7A5 gene.

Y+L amino acid transporter 2

Y+L amino acid transporter 2, also known as cationic amino acid transporter, y+ system, is a protein that in humans is encoded by the SLC7A6 gene.

Asc-type amino acid transporter 1

Asc-type amino acid transporter 1 (Asc-1) is a protein that in humans is encoded by the SLC7A10 gene.

Organic anion transporter 1

The organic anion transporter 1 (OAT1) also known as solute carrier family 22 member 6 (SLC22A6) is a protein that in humans is encoded by the SLC22A6 gene. It is a member of the organic anion transporter (OAT) family of proteins. OAT1 is a transmembrane protein that is expressed in the brain, the placenta, the eyes, smooth muscles, and the basolateral membrane of proximal tubular cells of the kidneys. It plays a central role in renal organic anion transport. Along with OAT3, OAT1 mediates the uptake of a wide range of relatively small and hydrophilic organic anions from plasma into the cytoplasm of the proximal tubular cells of the kidneys. From there, these substrates are transported into the lumen of the nephrons of the kidneys for excretion. OAT1 homologs have been identified in rats, mice, rabbits, pigs, flounders, and nematodes.

Monocarboxylate transporter 10

Monocarboxylate transporter 10, also known as aromatic amino acid transporter 1 and T-type amino acid transporter 1 (TAT1) and solute carrier family 16 member 10 (SLC16A10), is a protein that in humans is encoded by the SLC16A10 gene. SLC16A10 is a member of the solute carrier family.

Dicarboxylic aminoaciduria is a rare form of aminoaciduria which is an autosomal recessive disorder of urinary glutamate and aspartate due to genetic errors related to transport of these amino acids. Mutations resulting in a lack of expression of the SLC1A1 gene, a member of the solute carrier family, are found to cause development of dicarboxylic aminoaciduria in humans. SLC1A1 encodes for EAAT3 which is found in the neurons, intestine, kidney, lung, and heart. EAAT3 is part of a family of high affinity glutamate transporters which transport both glutamate and aspartate across the plasma membrane.

The Amino Acid-Polyamine-Organocation (APC) Family of transport proteins includes members that function as solute:cation symporters and solute:solute antiporters. They occur in bacteria, archaea, fungi, unicellular eukaryotic protists, slime molds, plants and animals. They vary in length, being as small as 350 residues and as large as 850 residues. The smaller proteins are generally of prokaryotic origin while the larger ones are of eukaryotic origin. Most of them possess twelve transmembrane α-helical spanners but have a re-entrant loop involving TMSs 2 and 3. The APC Superfamily was established to encompass a wider range of homologues.

References

  1. Wagner CA, Lang F, Bröer S (October 2001). "Function and structure of heterodimeric amino acid transporters". Am. J. Physiol., Cell Physiol. 281 (4): C1077–93. doi:10.1152/ajpcell.2001.281.4.C1077. PMID   11546643.