Equilibrative nucleoside transporter 1 (ENT1) is a protein that in humans is encoded by the SLC29A1 gene. [5] [6] Multiple alternatively spliced variants, encoding the same protein, have been found for this gene. [7] Expressed on red blood cell surfaces, these variants make up the Augustine blood group system. [8]
This gene is a member of the equilibrative nucleoside transporter family. The gene encodes a transmembrane glycoprotein that localizes to the plasma and mitochondrial membranes and mediates the cellular uptake of nucleosides from the surrounding medium. The protein is categorized as an equilibrative (as opposed to concentrative) transporter that is sensitive to inhibition by nitrobenzylmercaptopurine ribonucleoside (NBMPR). Nucleoside transporters are required for nucleotide synthesis in cells that lack de novo nucleoside synthesis pathways, and are also necessary for the uptake of cytotoxic nucleosides used for cancer and viral chemotherapies. [7]
The gene encoding this protein is located on the short arm of chromosome 6 at 6p21.2-p21.1 on the Watson (plus) strand. It is 14,647 bases in length. The encoded protein has 456 amino acid residues with 11 predicted transmembrane domains. The predicted molecular weight is 50.219 kilodaltons. The protein is post translationally glycosylated and expressed in all tissue with the apparent exception of skeletal muscle. The highest levels are found in the liver, heart, testis, spleen, lung, kidney and brain.
Click on genes, proteins and metabolites below to link to respective articles. [§ 1]
Mutations in this gene have been associated with H syndrome, pigmented hypertrichosis with insulin dependent diabetes and Faisalabad histiocytosis. [9]
Alleles of this gene make up the Augustine blood group system. [8] Some of the four known variants are highly immunogenic and antibodies against them can cause acute hemolytic transfusion reaction and hemolytic disease of the fetus and newborn. [10]
Uniporters, also known as solute carriers or facilitated transporters, are a type of membrane transport protein that passively transports solutes across a cell membrane. It uses facilitated diffusion for the movement of solutes down their concentration gradient from an area of high concentration to an area of low concentration. Unlike active transport, it does not require energy in the form of ATP to function. Uniporters are specialized to carry one specific ion or molecule and can be categorized as either channels or carriers. Facilitated diffusion may occur through three mechanisms: uniport, symport, or antiport. The difference between each mechanism depends on the direction of transport, in which uniport is the only transport not coupled to the transport of another solute.
Natural resistance-associated macrophage protein 2, also known as divalent metal transporter 1 (DMT1) and divalent cation transporter 1 (DCT1), is a protein that in humans is encoded by the SLC11A2 gene. DMT1 represents a large family of orthologous metal ion transporter proteins that are highly conserved from bacteria to humans.
RAC-gamma serine/threonine-protein kinase is an enzyme that in humans is encoded by the AKT3 gene.
Serine/threonine-protein kinase 4 is an enzyme that in humans is encoded by the STK4 gene.
Nucleoside diphosphate kinase B is an enzyme that in humans is encoded by the NME2 gene.
Class E basic helix-loop-helix protein 40 is a protein that in humans is encoded by the BHLHE40 gene.
Equilibrative nucleoside transporter 2 (ENT2) is a protein that in humans is encoded by the SLC29A2 gene.
Concentrative nucleoside transporter 2 (CNT2) is a protein that in humans is encoded by the SLC28A2 gene.
High affinity cationic amino acid transporter 1 is a protein that in humans is encoded by the SLC7A1 gene.
Concentrative nucleoside transporter 1 (CNT1) is a protein that in humans is encoded by the SLC28A1 gene.
Zinc transporter ZIP1 is a protein that in humans is encoded by the SLC39A1 gene.
Sodium-dependent multivitamin transporter is a protein that in humans is encoded by the SLC5A6 gene.
AP-3 complex subunit sigma-1 is a protein that in humans is encoded by the AP3S1 gene.
An adenosine reuptake inhibitor (AdoRI) is a type of drug which acts as a reuptake inhibitor for the purine nucleoside and neurotransmitter adenosine by blocking the action of one or more of the equilibrative nucleoside transporters (ENTs). This in turn leads to increased extracellular concentrations of adenosine and therefore an increase in adenosinergic neurotransmission.
The plasma membrane monoamine transporter (PMAT) is a low-affinity monoamine transporter protein which in humans is encoded by the SLC29A4 gene. It is known alternatively as the human equilibrative nucleoside transporter-4 (hENT4). It was discovered in 2004 and has been identified as a potential alternate target for treating various conditions.
Nucleoside transporters (NTs) are a group of membrane transport proteins which transport nucleoside substrates like adenosine across the membranes of cells and/or vesicles. There are two known types of nucleoside transporters, concentrative nucleoside transporters and equilibrative nucleoside transporters, as well as possibly a yet-unidentified vesicular transporter.
Solute carrier family 2, facilitated glucose transporter member 7 also known as glucose transporter 7 (GLUT7) is a protein that in humans is encoded by the SLC2A7 gene.
Human concentrative nucleoside transporters include SLC28A1, SLC28A2 and SLC28A3 proteins. SLC28A2 is a purine-specific Na+-nucleoside cotransporter localised to the bile canalicular membrane. SLC28A1 is a Na+-dependent nucleoside transporter selective for pyrimidine nucleosides and adenosine. It also transports the anti-viral nucleoside analogues Zidovudine and Zalcitabine.
Members of the Equilibrative Nucleoside Transporter (ENT) Family are transport proteins that are specific to nucleosides and nucleobases, and are part of the major facilitator superfamily. They generally possess at least 6, typically 10, transmembrane segments (TMSs) and are 300-600 amino acyl residues in length.
The Augustine blood group system is a human blood group system. It includes four red blood cell surface glycoprotein antigens which are encoded by alleles of the gene SLC29A1.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
