AHCYL2 (long-IRBIT) as a potential regulator of the electrogenic Na(+)-HCO3(-) cotransporter NBCe1-B

FEBS Lett. 2014 Mar 3;588(5):672-7. doi: 10.1016/j.febslet.2013.12.036. Epub 2014 Jan 25.

Abstract

Although AHCYL2 (long-IRBIT) is highly homologous to IRBIT, which regulates ion-transporting proteins including the electrogenic Na(+)-HCO3(-) cotransporter NBCe1-B, its functions are poorly understood. Here, we found that AHCYL2 interacts with NBCe1-B in bovine parotid acinar cells using yeast two-hybrid, immunofluorescence confocal microscopy and co-immunoprecipitation analyses. Whole-cell patch-clamp experiments revealed that co-expression of AHCYL2 reduces the apparent affinity for intracellular Mg(2+) in inhibition of NBCe1-B currents specifically in a HCO3(-)-deficient cellular condition. Our data unveil AHCYL2 as a potential regulator of NBCe1-B in mammalian cells. We propose that cytosolic ionic condition appropriate for AHCYL2 to function might be different from IRBIT.

Keywords: Bovine parotid acinar cell; IRBIT; Intracellular Mg(2+); Long-IRBIT; NBCe1-B; Whole-cell patch-clamp.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Gene Expression
  • HEK293 Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Magnesium / metabolism*
  • Membrane Potentials
  • Parotid Gland / cytology
  • Patch-Clamp Techniques
  • Protein Binding
  • Protein Transport
  • Sodium-Bicarbonate Symporters / metabolism*
  • Two-Hybrid System Techniques

Substances

  • Intracellular Signaling Peptides and Proteins
  • Sodium-Bicarbonate Symporters
  • Magnesium