SLC4A4 cotransports Na+ with 3HCO3-

Stable Identifier
Reaction [transition]
Homo sapiens
Locations in the PathwayBrowser
SVG |   | PPTX  | SBGN
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout

SLC4A family members 4, 5, 7, and 9 can each couple the transport of bicarbonate (HCO3-) with sodium ions (Na+). SLC4A4 (aka NBCE1) is an electrogenic sodium/bicarbonate cotransporter with a Na+:HCO3- stoichiometry of 1:3, although it can also be 1:2 (Burnham et al. 1997). SLC4A4 encodes a protein which is expressed in the kidney and pancreas, with lesser expression in many other tissues (Abuladze et al. 1998). Mutations in SLC4A4 cause permanent isolated proximal renal tubular acidosis (pRTA) (results in accumulation of acid in the body due to a failure of the kidneys to effectively acidify urine) with ocular abnormalities (Igarashi et al. 1999).

Adenosylhomocysteinase 2 (AHCYL2) can upregulate ion-transporting proteins such as the electrogenic sodium bicarbonate cotransporter 1 (SLC4A4, aka NBCE1) (Yamaguchi & Ishikawa 2014).

Literature References
PubMed ID Title Journal Year
9651366 Molecular cloning, chromosomal localization, tissue distribution, and functional expression of the human pancreatic sodium bicarbonate cotransporter

Newman, D, Boorer, K, Pushkin, A, Hwang, J, Abuladze, N, Kurtz, I, Lee, I

J Biol Chem 1998
10545938 Mutations in SLC4A4 cause permanent isolated proximal renal tubular acidosis with ocular abnormalities

Tozawa, F, Cha, SH, Igarashi, T, Satoh, H, Kanai, Y, Seki, G, Shiobara, M, Shimadzu, M, Endou, H, Kunimi, M, Mori, T, Tsukamoto, K, Inatomi, J, Sekine, T

Nat Genet 1999
9235899 Cloning and functional expression of a human kidney Na+:HCO3- cotransporter

Wang, Z, Soleimani, M, Shull, GE, Burnham, CE, Amlal, H

J Biol Chem 1997
24472682 AHCYL2 (long-IRBIT) as a potential regulator of the electrogenic Na(+)-HCO3(-) cotransporter NBCe1-B

Yamaguchi, S, Ishikawa, T

FEBS Lett. 2014
Catalyst Activity

sodium:bicarbonate symporter activity of SLC4A4 [plasma membrane]

This event is regulated
Positively by