Posttranscriptional regulation of ATA2 transport during liver regeneration

Thomas L. Freeman, Mark E Mailliard

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

The recent cloning of ATA2, a cDNA displaying characteristics identical to the System A transporter, has provided the first molecular tool for study of System A-mediated amino acid transport in liver. Despite the 233 ± 9 and 472 ± 11% increase in System A transport activity following partial hepatectomy at 6 and 12 h, respectively, the steady-state level of ATA2 mRNA did not show a corresponding marked increase. Examination of the kinetic properties of System A following partial hepatectomy revealed a K(m) of 0.26 ± 0.04 mM which is consistent with the reported K(m) for ATA2. These results indicate that a System A transporter present in regenerating liver and ATA2 are identical, but that the increase in System A activity following partial hepatectomy does not result from an increase in steady-state levels of ATA2 mRNA. These observations suggest that ATA2-mediated transport of amino acids is regulated at the posttranscriptional level. (C) 2000 Academic Press.

Original languageEnglish (US)
Pages (from-to)729-732
Number of pages4
JournalBiochemical and Biophysical Research Communications
Volume278
Issue number3
DOIs
Publication statusPublished - Nov 30 2000

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Keywords

  • ATA2
  • Amino acid transport
  • Liver regeneration
  • Partial hepatectomy
  • SA1
  • System A

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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