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SLC36 family of proton-coupled amino acid transporters C

Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).


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Members of the SLC36 family of proton-coupled amino acid transporters are involved in membrane transport of amino acids and derivatives [28-29]. The four transporters show variable tissue expression patterns and are expressed in various cell types at the plasma-membrane and in intracellular organelles. PAT1 is expressed at the luminal surface of the small intestine and absorbs amino acids and derivatives [4]. In lysosomes, PAT1 functions as an efflux mechanism for amino acids produced during intralysosomal proteolysis [2,25]. PAT2 is expressed at the apical membrane of the renal proximal tubule [7] and at the plasma-membrane in brown/beige adipocytes [30]. PAT1 and PAT4 are involved in regulation of the mTORC1 pathway [11,27]. More comprehensive lists of substrates can be found within the reviews under Further Reading and in the references [3].


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PAT1 (Proton-coupled Amino acid Transporter 1 / SLC36A1) C Show summary »

Target Id 1161
Nomenclature Proton-coupled Amino acid Transporter 1
Systematic nomenclature SLC36A1
Common abbreviation PAT1
Previous and unofficial names LYAAT-1 | Tramdorin-3 | imino acid carrier | TRAMD3 | solute carrier family 36 member 1 | proton/amino acid transporter 1 | proton-coupled amino acid transporter 1 | lysosomal amino acid transporter 1 | solute carrier family 36 (proton/amino acid symporter), member 1 | System PAT | solute carrier family 36 (proton/amino acid symporter)
Genes SLC36A1 (Hs), Slc36a1 (Mm), Slc36a1 (Rn)
Ensembl ID ENSG00000123643 (Hs), ENSMUSG00000020261 (Mm), ENSRNOG00000012356 (Rn)
UniProtKB AC Q7Z2H8 (Hs), Q8K4D3 (Mm), Q924A5 (Rn)
Bioparadigms SLC Tables SLC36A1 (Hs)
Endogenous substrates
L-alanine [29]
glycine [29]
GABA [29]
β-alanine [29]
taurine [29]
D-serine [29]
D-cysteine [29]
D-proline [29]
D-alanine [29]
trans-4-hydroxy-proline [29]
sarcosine [29]
muscimol [29]
gaboxadol [17,29]
betaine [29]
L-azetidine-2-carboxylate [29]
MeAIB [29]
β-guanidinopropionic acid [29]
THPO [29]
5-aminolevulinic acid [29]
vigabatrin [1,29]
arecaidine [29]
L-cycloserine [29]
D-cycloserine [29]
nicotianamine-Fe(II) complex [19]
5-hydroxy-L-tryptophan pKi 3.0 [18]
L-tryptophan pKi 2.3 [18]
indole-3-propionic acid pKi 2.3 [18]
5-hydroxytryptamine pKi 2.2 [18]
17β-estradiol pIC50 5.0 – 5.2 [21]
ethinylestradiol pIC50 4.3 – 4.6 [21]
Stoichiometry 1 H+ : 1 amino acid (symport)
Comment [3H] or [14C] labelled substrates as listed above are used as probes. PAT1 can also function as an electroneutral transport system for protons and short chain fatty acids including acetic acid, propanoic acid and butyric acid [14]. In addition, forskolin, phosphodiesterase inhibitors, amiloride analogues and SLC9A3 (NHE3) selective inhibitors all reduce PAT1 activity indirectly (in intact mammalian intestinal epithelia such as human intestinal Caco-2 cells) by inhibiting the Na+/H+ exchanger NHE3 which is required to maintain the H+-electrochemical gradient driving force for H+/amino acid cotransport [4-5,29].

PAT2 (Proton-coupled Amino acid Transporter 2 / SLC36A2) C Show summary »

PAT3 (Proton-coupled Amino acid Transporter 3 / SLC36A3) C Show summary »

PAT4 (Proton-coupled Amino acid Transporter 4 / SLC36A4) C Show summary »


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Further reading

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NC-IUPHAR subcommittee and family contributors

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How to cite this family page

Database page citation (select format):

Concise Guide to PHARMACOLOGY citation:

Alexander SPH, Fabbro D, Kelly E, Mathie AA, Peters JA, Veale EL, Armstrong JF, Faccenda E, Harding SD, Davies JA et al. (2023) The Concise Guide to PHARMACOLOGY 2023/24: Transporters. Br J Pharmacol. 180 Suppl 2:S374-469.