SLC7A7 Gene

The SLC7A7 gene (SLC7A7 stands for "Solute Carrier Family 7 Member 7") is a protein-coding gene located on chromosome 14q11.2. Alternative splicing results in multiple transcript variants.

The protein encoded by the SLC7A7 gene is the light subunit of a cationic amino acid transporter. This sodium-independent transporter is formed by dimerization of the SLC7A7 protein with the heavy subunit transporter protein SLC3A2. The now dimerized transporter protein complex SLC7A7/ SLC3A2 is found in the membranes of epithelial cells, where it transports cationic and large neutral amino acids out of the cell into the extracellular space.

Furthermore, the complex is involved in the sodium-independent uptake of dibasic amino acids and the sodium-dependent uptake of some neutral amino acids. Furthermore, the complex plays a role in nitric oxide synthesis in human umbilical vein endothelial cells (HUVECs) via the transport of L-arginine. It is involved in the transport of L-arginine in monocytes.

Defects in this gene are a cause of "lysinuric protein intolerance (LPI)" lysinuric protein intolerance (LPI; OMIM: 222700), also known as aminoaciduria, hyperdibasic, type 2. In LPI, cationic ('basic') amino acids are excreted more in the urine and reabsorbed less in the intestine. There is concomitant orotaciduria and immunodeficiency.

1. Font-Llitjos M et al. (2009) Novel SLC7A7 large rearrangements in lysinuric protein intolerance patients involving the same AluY repeat. Europ J Hum Genet 17: 71-79.
2. Kato T et al (1982) Renal transport of lysine and arginine in lysinuric protein intolerance. Europ J Pediat 139: 181-184.
3. Kekomaki M et al (1968) Familial protein intolerance with deficient transport of basic amino acids. Report on an adult patient with chronic hyperammonemia Acta Med Scand 183: 357-359.
4. Noguchi A et al. (2019) Overview of symptoms and treatment for lysinuric protein intolerance. J Hum Genet 64:849-858.