The ABC of Solute carriers Guest Editor: Matthias A. Hediger

Pflügers Archiv

, Volume 447, Issue 5, pp 532-542

First online:

CATs and HATs: the SLC7 family of amino acid transporters

  • François VerreyAffiliated withInstitute of Physiology, University of Zürich Email author 
  • , Ellen I. ClossAffiliated withDepartment of Pharmacology, Johannes Gutenberg University
  • , Carsten A. WagnerAffiliated withInstitute of Physiology, University of Zürich
  • , Manuel PalacinAffiliated withDepartment of Biochemistry and Molecular Biology, University of Barcelona
  • , Hitoshi EndouAffiliated withDepartment of Pharmacology and Toxicology, Kyorin University School of Medicine
  • , Yoshikatsu KanaiAffiliated withDepartment of Pharmacology and Toxicology, Kyorin University School of Medicine

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The SLC7 family is divided into two subgroups, the cationic amino acid transporters (the CAT family, SLC7A1–4) and the glycoprotein-associated amino acid transporters (the gpaAT family, SLC7A5–11), also called light chains or catalytic chains of the hetero(di)meric amino acid transporters (HAT). The associated glycoproteins (heavy chains) 4F2hc (CD98) or rBAT (D2, NBAT) form the SLC3 family. Members of the CAT family transport essentially cationic amino acids by facilitated diffusion with differential trans-stimulation by intracellular substrates. In some cells, they may regulate the rate of NO synthesis by controlling the uptake of l-arginine as the substrate for nitric oxide synthase (NOS). The heterodimeric amino acid transporters are, in contrast, quite diverse in terms of substrate selectivity and function (mostly) as obligatory exchangers. Their selectivity ranges from large neutral amino acids (system L) to small neutral amino acids (ala, ser, cys-preferring, system asc), negatively charged amino acid (system xc ) and cationic amino acids plus neutral amino acids (system y+L and b0,+-like). Cotransport of Na+ is observed only for the y+L transporters when they carry neutral amino acids. Mutations in b0,+-like and y+L transporters lead to the hereditary diseases cystinuria and lysinuric protein intolerance (LPI), respectively.


Cationic amino acid transporter Glycoprotein-associated amino acid transporter Heterodimeric amino acid transporter CAT1 LAT1 b0,+AT xCT Asc-1 Cystinuria Lysinuric protein intolerance