Archives of Pharmacal Research

, Volume 28, Issue 4, pp 421–432

Reabsorption of neutral amino acids mediated by amino acid transporter LAT2 and TAT1 in the basolateral membrane of proximal tubule

  • Sun Young Park
  • Jong-Keun Kim
  • In Jin Kim
  • Bong Kyu Choi
  • Kyu Yong Jung
  • Seoul Lee
  • Kyung Jin Park
  • Arthit Chairoungdua
  • Yoshikatsu Kanai
  • Hitoshi Endou
  • Do Kyung Kim
Drug development

DOI: 10.1007/BF02977671

Cite this article as:
Park, S.Y., Kim, JK., Kim, I.J. et al. Arch Pharm Res (2005) 28: 421. doi:10.1007/BF02977671

Abstract

In order to understand the renal reabsorption mechanism of neutral amino acids via amino acid transporters, we have isolated human L-type amino acid transporter 2 (hLAT2) and human T-type amino acid transporter 1 (hTAT1) in human, then, we have examined and compared the gene structures, the functional characterizations and the localization in human kidney. Northern blot analysis showed that hLAT2 mRNA was expressed at high levels in the heart, brain, placenta, kidney, spleen, prostate, testis, ovary, lymph node and the fetal liver. The hTAT1 mRNA was detected at high levels in the heart, placenta, liver, skeletal muscle, kidney, pancreas, spleen, thymus and prostate. Immunohistochemical analysis on the human kidney revealed that the hLAT2 and hTAT1 proteins coexist in the basolateral membrane of the renal proximal tubules. The hLAT2 transports all neutral amino acids and hTAT1 transports aromatic amino acids. The basolateral location of the hLAT2 and hTAT1 proteins in the renal proximal tubule as well as the amino acid transport activity of hLAT2 and hTAT1 suggests that these transporters contribute to the renal reabsorption of neutral and aromatic amino acids in the basolateral domain of epithelial proximal tubule cells, respectively. Therefore, LAT2 and TAT1 play essential roles in the reabsorption of neutral amino acids from the epithelial cells to the blood stream in the kidney. Because LAT2 and TAT1 are essential to the efficient absorption of neutral amino acids from the kidney, their defects might be involved in the pathogenesis of disorders caused by a disruption in amino acid absorption such as blue diaper syndrome.

Key words

L-Type amino acid transporter 2 (LAT2) T-Type amino acid transporter 1 (TAT1) Amino acids Reabsorption mechanism Kidney 

Copyright information

© The Pharmaceutical Society of Korea 2005

Authors and Affiliations

  • Sun Young Park
    • 1
    • 5
  • Jong-Keun Kim
    • 2
    • 5
  • In Jin Kim
    • 5
  • Bong Kyu Choi
    • 3
    • 5
  • Kyu Yong Jung
    • 3
    • 5
  • Seoul Lee
    • 3
    • 5
  • Kyung Jin Park
    • 5
  • Arthit Chairoungdua
    • 4
    • 5
  • Yoshikatsu Kanai
    • 4
    • 5
  • Hitoshi Endou
    • 4
    • 5
  • Do Kyung Kim
    • 5
  1. 1.Department of PediatricsKwangju Christian HospitalGwangjuKorea
  2. 2.Department of PharmacologyChonnam National University Medical SchoolGwangjuKorea
  3. 3.Department of PharmacologyWonkwang University School of MedicineIksanKorea
  4. 4.Department of Pharmacology and ToxicologyKyorin University School of MedicineTokyoJapan
  5. 5.Department of Oral PhysiologyChosun University College of DentistryGwangjuKorea

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