AHCYL2 (long-IRBIT) as a potential regulator of the electrogenic Na(+)-HCO3(-) cotransporter NBCe1-B.
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.
Laboratory of Physiology, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Soichiro
S
Yamaguchi
Laboratory of Physiology, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan. Electronic address: torui@obihiro.ac.jp.
Toru
T
Ishikawa
D000818:Animals; D002417:Cattle; D015870:Gene Expression; D057809:HEK293 Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism*; D008564:Membrane Potentials; D010306:Parotid Gland / Q000166:cytology; D018408:Patch-Clamp Techniques; D011485:Protein Binding; D021381:Protein Transport; D027982:Sodium-Bicarbonate Symporters / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D047908:Intracellular Signaling Peptides and Proteins; D027982:Sodium-Bicarbonate Symporters; D008274:Magnesium
Bovine parotid acinar cell; IRBIT; Intracellular Mg(2+); Long-IRBIT; NBCe1-B; Whole-cell patch-clamp