Amino acid transporter B0AT1 (slc6a19) and ancillary protein: impact on function

Eleonora Margheritis, Francesca Guia Imperiali, Raffaella Cinquetti, Alessandra Vollero, Genciana Terova, Simona Rimoldi, Rossana Girardello, Elena Bossi

Research output: Contribution to journalArticle

Abstract

Amino acids play an important role in the metabolism of all organisms. Their epithelial re-absorption is due to specific transport proteins, such as B0AT1, a Na+-coupled neutral amino acid symporter belonging to the solute carrier 6 family. Here, a recently cloned fish orthologue, from the intestine of Salmo salar, was electrophysiologically characterized with the two-electrode voltage clamp technique, in Xenopus laevis oocytes heterologously expressing the transporter. Substrate specificity, apparent affinities and the ionic dependence of the transport mechanism were determined in the presence of specific collectrin. Results demonstrated that like the human, but differently from sea bass (Dicentrarchus labrax) orthologue, salmon B0AT1 needs to be associated with partner proteins to be correctly expressed at the oocyte plasma membrane. Cloning of sea bass collectrin and comparison of membrane expression and functionality of the B0AT1 orthologue transporters allowed a deeper investigation on the role of their interactions. The parameters acquired by electrophysiological and immunolocalization experiments in the mammalian and fish transporters contributed to highlight the dynamic of relations and impacts on transport function of the ancillary proteins. The comparative characterization of the physiological parameters of amino acid transporters with auxiliary proteins can help the comprehension of the regulatory mechanism of essential nutrient absorption.

Original languageEnglish
Pages (from-to)1-12
Number of pages12
JournalPflugers Archiv European Journal of Physiology
DOIs
Publication statusAccepted/In press - Jun 2 2016

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Keywords

  • Collectrin
  • Membrane transporter
  • Neutral amino acid transporters
  • TEVC
  • Xenopus laevis oocytes

ASJC Scopus subject areas

  • Physiology
  • Clinical Biochemistry
  • Physiology (medical)

Cite this

Margheritis, E., Imperiali, F. G., Cinquetti, R., Vollero, A., Terova, G., Rimoldi, S., Girardello, R., & Bossi, E. (Accepted/In press). Amino acid transporter B0AT1 (slc6a19) and ancillary protein: impact on function. Pflugers Archiv European Journal of Physiology, 1-12. https://doi.org/10.1007/s00424-016-1842-5