TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameOrganismal TypeExample
2.A.18.1.1









Auxin:H+ symporter (auxin influx), AUX or LAX (Reinhardt et al., 2003; Carraro et al., 2012)

Plants

Aux-1 of Arabidopsis thaliana
2.A.18.2.1









General amino acid permease 1, AAP1 (transports most neutral and acidic amino acids but not aspartate or the basic amino acids)
Plants
AAP1 of Arabidopsis thaliana
2.A.18.2.2









Lysine/histidine transporter, LHT1
Plants
LHT1 of Arabidopsis thaliana
2.A.18.2.3









General amino acid transporter 3, AAP3 (transports all neutral, acidic and basic amino acids tested)
Plants
AAP3 of Arabidopsis thaliana
2.A.18.2.4









General amino acid transporter 6, AAP6 (transports all neutral and acidic amino acids tested including aspartate, and basic amino acids are transported with low affinity) (Okumoto et al., 2002)
Plants
AAP6 of Arabidopsis thaliana
2.A.18.2.5









General amino acid transporter 8, AAP8 (transports all amino acids, but the basic amino acids are transported
with low affinity (Okumoto et al., 2002))
Plants
AAP8 of Arabidopsis thaliana
2.A.18.2.6









Lysine-Histidine Transporter-7 (LHT7) found in mature pollen (Bock et al., 2006) (most like 2.A.18.2.2; 30% identity)

Plants

LHT7 of Arabidopsis thaliana (Q84WE9)
2.A.18.2.7









Amino acid permease 2 (Amino acid transporter AAP2)
Plants
AAP2 of Arabidopsis thaliana
2.A.18.2.8









Lysine histidine transporter-like 8 (Amino acid transporter-like protein 1)
Plants
AATL1 of Arabidopsis thaliana
2.A.18.2.9









Lysine/histidine transporter 2 (AtLHT2) (Amino acid transporter-like protein 2)

Plants
LHT2 of Arabidopsis thaliana
2.A.18.2.10









Probable amino acid permease 7 (Amino acid transporter AAP7)
Plants
AAP7 of Arabidopsis thaliana
2.A.18.3.1









Proline permease 1
Plants
Prt1 of Arabidopsis thaliana
2.A.18.3.2









Proline/GABA/glycine betaine permease, ProT1
Plants
ProT1 of Lycopersicon esculentum
2.A.18.4.1









Neutral amino acid permease
Fungi
AAP1 of Neurospora crassa
2.A.18.4.2









Aromatic and neutral amino acid permease, PcMtr (Trip et al., 2004)
Fungi
PcMtr of Penicillium chrysogenum (AAT45727)
2.A.18.5.1









Vesicular γ-aminobutyric acid (GABA) and glycine transporter (Aubrey et al., 2007)

Animals

UNC-47 of Caenorhabditis elegans
2.A.18.5.2









The vacuolar amino acid transporter AVT1 (catalyzes uptake into yeast vacuoles of large neutral amino acids including tyr, gln, asn, leu and ile)
Yeast
AVT1 of Saccharomyces cerevisiae
2.A.18.5.3









The vacuolar GABA and glycine uptake transporter, VGAT. Also called "vesicular inhibitory amino acid transporter" (VIAAT); it is a 2Cl-/γ-aminobutyrate or glycine co-transporter in synaptic vesicles (Juge et al., 2009). GlyT2 and VIAAT cooperate to determine the vesicular glycinergic phenotype (Aubrey et al., 2007).

Animals

VGAT of Mus musculus (O35633)
2.A.18.5.4









Vesicular inhibitory amino acid transporter (GABA and glycine transporter) (Solute carrier family 32 member 1) (Vesicular GABA transporter) (hVIAAT)
Animals
SLC32A1 of Homo sapiens
2.A.18.6.1









Neuronal glutamine (System A-like) transporter, GlnT
Animals
GlnT of Rattus norvegicus (Q9JM15)
2.A.18.6.2









Liver histidine and glutamine specific system N-like, Na+-dependent amino acid transporter, mNAT. Also called SNAT3. SNAT3 trafficking occurs in a dynamin-independent manner and is influenced by caveolin (Balkrishna et al., 2010).

Animals

mNAT of Mus musculus (Q9JLL8)
2.A.18.6.3









System N1 [glutamine/histidine/asparagine/alanine]:[Na+ + H+] sym/antiporter (1 aa + 2 Na+ cotransported against 1 H+ antiported out) (probable orthologue of mNAT). Li+ can substitute for Na+; system N1 can function bidirectionally.
Animals
SLC38A3 of Homo sapiens
2.A.18.6.4









Plasma membrane System A-like neutral amino acid transporter, SA1, SAT2 or SNAT2 (transports small, neutral aliphatic amino acids including α-(methylamino)isobutyrate, mAIB with Na+ (1:1 stoichiometry; Km = 200-500 μM)). Asparagine 82 controls the interaction of Na+ with the transporter (Zhang and Grewer, 2007). The C-terminal domain regulates transport activity through a voltage-dependent process (Zhang et al., 2011).

Animals

SAT2 of Rattus norvegicus (Q9JHE5)
2.A.18.6.5









Na+-dependent system A-like transporter, System A2 or ATA2 (transports neutral amino acids with decreasing affinity in the order: MeAIB, Ala, Gly, Ser, Pro, Met, Asn, Gln, Thr, Leu and Phe). The neuronal system A2 has been reported to transport Asn and Gln with higher affinity than for other neutral amino acids. [ATA2 is stored in the Golgi network and released by insulin stimulus in adipocytes (Hatanaka et al., 2006a).] Its levels are regulated by ubiquitin ligase, Nedd4-2, which causes endocytotic sequestration and proteosomal degradation (Hatanaka et al., 2006b). SNAT2 also functions as a mammalian amino acid transceptor (transporter/receptor), acting in an autoregulatory gene expression pathway (Hyde et al., 2007). It also mediates an anion leak conductance that is differentially inhibited by transported substrates (Zhang and Grewer, 2007). Also transports homocysteine (Tsitsiou et al., 2009).
Animals
SLC38A2 of Homo sapiens
2.A.18.6.6









The vacuolar amino acid transporter, AVT6 (catalyzes efflux from yeast vacuoles of acidic amino acids, Asp and Glu)
Yeast
AVT6 of Saccharomyces cerevisiae (P40074)
2.A.18.6.7









The Na-dependent alanine/α-(methylamino) isobutyric acid-transporting system A, ATA3 or SNAT4. Transports most neutral short chain amino acids electrogenically. Present only in liver and skeletal muscle. 47% and 57% identical to ATA1 and ATA2, respectively. A 10TMS topology [with N-and C-termini outside and a large N-glycosylated, extracellular loop domain (residues 242-335)] has been established (Shi et al., 2011). (Km(ALA)= 4mM; Na+:Ala= 1:1) (Sugawara et al., 2000)

Animals

ATA3 of Rattus norvegicus (Q9EQ25)
2.A.18.6.8









Second subtype of system N; glutamine transporter, SN2. Prevalent in liver, but detectable in other tissues. Amino acid uptake is coupled to Na+ influx and H+ efflux (Nakanishi et al., 2001)

Animals

SN2 of Rattus norvegicus (Q91XR7)
2.A.18.6.9









Arginine-specific transporter, AAP3 (KM (Arg) = 2μM)
Protozoa
AAP3 of Leishmania donovani (Q86G79)
2.A.18.6.10









Vacuolar broad specificity amino acid transporter 5 Avt5. Transports histidine, gluatmate, tyrosine, arginine, lysine and serine (Chardwiriyapreecha et al., 2010).

Yeast

Avt5 of Saccharomyces cerevisiae (P38176)
2.A.18.6.11









SLC38 member 6. Na+-dependent synaptic vesicle amino acid release porter (Gasnier, 2004) (transports inhibitory amino acids, glycine and γ-amino butyric acid (GABA)). May catalyze amino acid:H+ exchange 

Animals
SLC38A6 of Homo sapiens
2.A.18.6.12









solute carrier family 38, member 8
Animals
SLC38A8 of Homo sapiens
2.A.18.6.13









Putative sodium-coupled neutral amino acid transporter 7
Animals
SLC38A7 of Homo sapiens
2.A.18.6.14









Sodium-coupled neutral amino acid transporter 1 (Amino acid transporter A1) (N-system amino acid transporter 2) (Solute carrier family 38 member 1) (System A amino acid transporter 1) (System N amino acid transporter 1)
Animals
SLC38A1 of Homo sapiens
2.A.18.6.15









Sodium-coupled neutral amino acid transporter 5 (Solute carrier family 38 member 5) (System N transporter 2)
Animals
SLC38A5 of Homo sapiens
2.A.18.6.16









Putative sodium-coupled neutral amino acid transporter 10
Animals
SLC38A10 of Homo sapiens
2.A.18.6.17









Sodium-coupled neutral amino acid transporter 4 (Amino acid transporter A3) (Na(+)-coupled neutral amino acid transporter 4) (Solute carrier family 38 member 4) (System A amino acid transporter 3) (System N amino acid transporter 3)
Animals
SLC38A4 of Homo sapiens
2.A.18.6.18









Putative sodium-coupled neutral amino acid transporter 11
Animals
SLC38A11 of Homo sapiens
2.A.18.6.19









Vacuolar amino acid transporter 7
Fungi
AVT7 of Saccharomyces cerevisiae
2.A.18.6.20









Vacuolar amino acid transporter 2
Fungi
AVT2 of Saccharomyces cerevisiae
2.A.18.7.1









The vacuolar amino acid transporter, AVT3 (catalyzes efflux from yeast vacuoles of large neutral amino acids such as tyr, gln, asn, leu and ile)
Yeast
AVT3 of Saccharomyces cerevisiae
2.A.18.7.2









Vacuolar amino acid transporter 4
Fungi
AVT4 of Saccharomyces cerevisiae
2.A.18.7.3









Vacuolar amino acid transporter 3, Avt3.  Catalyzes efflux from vacuoles of large hydrophobic and hydrophilic neutral amino acids, and is required for sporulation.

Yeast

Avt3 of Schizosaccharomyces pombe
2.A.18.8.1









The electrogenic, proton-dependent amino acid:H+ symporter, PAT1 (Slc36A1) (catalyzes uptake of L-Gly, L-Ala, L-Pro, γ-amino butyrate, and short chain D-amino acids) (proline, hydroxproline: H+ = 1:1) (found in lysosomes) In humans, this is the iminoglycinuria protein (Boll et al., 2004Miyauchi et al., 2005; Broer, 2008). A disulfide bridge is essential for transport function (Dorn et al., 2009). Transports taurine and β-alanine by H+ symport with low affinity and high capacity across the intestinal brush boarder membrane (Anderson et al., 2009). Exhibits low affinity (Km= 1-10 mM) and transports amino acid-based drugs used to treat epilepsy, schizophrenia, bacterial infections, hyperglycemia and cancer (Thwaites and Anderson, 2011).

Animals

mPAT1 of Mus musculus (Q8K4D3)
2.A.18.8.2









Electrogenic, proton-coupled, amino acid symporter 2 (PAT2; Tramdorin-1; SLC36A2) (transports small amino acids: glycine, alanine and proline; found in the ER, not in lysosomes, of neuronal cells in the brain and spinal cord; it can catalyze bidirectional transport depending on the driving force) (Boll et al., 2004Rubio-Aliaga et al., 2004). SLC36A2 is expressed at the apical surface of the human renal proximal tubule where it functions in the reabsorption of glycine, proline, hydroxyproline and amino acid derivatives with narrower substrate selectivity and higher affinity (Km 0.1-0.7 mM) than SLC36A1. Mutations in SLC36A2 lead to hyperglycinuria and iminoglycinuria.

Animals

PAT2 of Mus musculus (AAH44800)
2.A.18.8.3









Amino acid transporter (low capacity, high affinity) and amino acid-dependent signal transduction protein, Pathetic (Path) (Goberdhan et al., 2005)
Animals
Path of Drosophila melanogaster (Q9VT04)
2.A.18.8.4









H+-coupled amino acid transporter-3 (SLC36A3).  SLC36A3 is expressed only in testes and has no known function (Thwaites and Anderson 2011).

Animals

SLC36A3 of Homo sapiens
2.A.18.8.5









H+-coupled amino acid transporter-4; SLC36A4.  SLC36A4 is widely distributed  and has high-affinity (Km = 2-3 µM) for proline and tryptophan (Thwaites and Anderson 2011).

Animals

SLC36A4 of Homo sapiens
2.A.18.8.6









Proton-coupled amino acid transporter 2 (Proton/amino acid transporter 2) (Solute carrier family 36 member 2) (Tramdorin-1)
Animals
SLC36A2 of Homo sapiens
2.A.18.8.7









Proton-coupled amino acid transporter 1 (Proton/amino acid transporter 1) (hPAT1) (Solute carrier family 36 member 1).  SLC36A1 is expressed at the luminal surface of the small intestine but is also commonly found in lysosomes in many cell types (including neurones), suggesting that it is a multipurpose carrier with distinct roles in different cells including absorption in the small intestine and as an efflux pathway following intralysosomal protein breakdown. SLC36A1 has a relatively low affinity (K(m) 1-10 mM) for its substrates, which include zwitterionic amino and imino acids, heterocyclic amino acids and amino acid-based drugs and derivatives used experimentally and/or clinically to treat epilepsy, schizophrenia, bacterial infections, hyperglycaemia and cancer (Thwaites and Anderson 2011).  hPAT1 transports the pyridine alkaloids, arecaidine, guvacine and isoguvacine, across the apical membrane of enterocytes and might be responsible for the intestinal absorption of these drug candidates (Voigt et al. 2013).

Animals

SLC36A1 of Homo sapiens
2.A.18.8.8









Putative amino acid permease F59B2.2
Worm
F59B2.2 of Caenorhabditis elegans
2.A.18.9.1









Putative Na+-coupled amino acid transporter, SLC38A9 (561aas; 11 TMSs)

Animals
SLC38A9 of Homo sapiens
2.A.18.10.1









Putative amino acid transporter, AAT

Animals

AAT of Homo sapiens (Q8NE00)
2.A.18.10.2









Putative amino acid transporter, AAT

Amoebozoa

AAT of Entamoeba histolytica (C4LSN3)
2.A.18.10.3









Putative amino acid transporter, AAT

Diplomonadida

AAT of Giardia intestinalis (C6LXJ3)
2.A.18.10.4









AAAP homologue

Ciliates

AAAP homologue of Tetrahymena thermophilus