title: The small SLC43 family: facilitator system l amino acid transporters and the orphan EEG1.
abstract: The SLC43 family is composed of only three genes coding for the plasma membrane facilitator system l amino acid transporters LAT3 (SLC43A1; TC 2.A.1.44.1) and LAT4 (SLC43A2; TC 2.A.1.44.2), and the orphan protein EEG1 (SLC43A3; TC 2.A.1.44.3). Besides the known mechanism of transport of LAT3 and LAT4, their physiological roles still remain quite obscure. Morphants suggested a role of LAT3 in renal podocyte development in zebrafish. Expression in liver and skeletal muscle, and up-regulation by starvation suggest a role of LAT3 in the flux of branched-chain amino acids (BCAAs) from liver and skeletal muscle to the bloodstream. Finally, LAT3 is up-regulated in androgen-dependent cancers, suggesting a role in mTORC1 signaling in this type of tumors. In addition, LAT4 might contribute to the transfer of BCAAs from mother to fetus. Unfortunately, the EEG1 mouse model (EEG1(Y221∗)) described here has not yet offered a clue to the physiological role of this orphan protein.
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelona), Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, and Centro de Investigación Biomedica en Red de Enfermedades Raras, E-08028 Barcelona, Spain.
authors.forename: Susanna
authors.initials: S
authors.lastname: Bodoy
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Fotiadis
authors.forename: Claudia
authors.initials: C
authors.lastname: Stoeger
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Kanai
authors.forename: Manuel
authors.initials: M
authors.lastname: Palacín
mesh_terms: D027241:Amino Acid Transport System y+L / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D026905:Amino Acid Transport Systems / Q000378:metabolism; D026923:Amino Acid Transport Systems, Basic / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D015152:Blotting, Northern; D006801:Humans; D008099:Liver / Q000378:metabolism; D000076222:Mechanistic Target of Rapamycin Complex 1; D008958:Models, Molecular; D005810:Multigene Family / Q000235:genetics*; D046912:Multiprotein Complexes / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D050199:Podocytes / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
chemical_list: D027241:Amino Acid Transport System y+L; D026905:Amino Acid Transport Systems; D026923:Amino Acid Transport Systems, Basic; D000596:Amino Acids; D046912:Multiprotein Complexes; D009363:Neoplasm Proteins; C115131:SLC43A1 protein, human; C000605140:SLC43A3 protein, human; C469951:SLC7A6 protein, human; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases