b(0,+)-type amino acid transporter 1, also known as b(0,+)AT1, is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

which in humans is encoded by the ''SLC7A9''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

Function

This gene encodes a protein that belongs to a family of light subunits of

amino acid transporter An amino acid transporter is a membrane transport protein that transports amino acids. They are mainly of the solute carrier family. Families There are several families that function in amino acid transport, some of these include: TC# 2.A.3- ...

s. This protein plays a role in the high-affinity and sodium-independent transport of

cystine Cystine is the oxidized derivative of the amino acid cysteine and has the formula (SCH2CH(NH2)CO2H)2. It is a white solid that is poorly soluble in water. As a residue in proteins, cystine serves two functions: a site of redox reactions and a me ...

and neutral and dibasic amino acids, and appears to function in the reabsorption of cystine in the kidney tubule. The protein associates with the protein coded for by

SLC3A1 Neutral and basic amino acid transport protein rBAT is a protein that in humans is encoded by the ''SLC3A1'' gene. Mutations in the SLC3A1 gene are associated with cystinuria. See also * Heterodimeric amino acid transporter * Solute carrier fam ...

Clinical significance

Mutations in this gene cause non-type I

cystinuria Cystinuria is an inherited autosomal recessive disease characterized by high concentrations of the amino acid cystine in the urine, leading to the formation of cystine stones in the kidneys, ureters, and bladder. It is a type of aminoaciduria. ...

, a disease that leads to cystine stones in the urinary system due to impaired transport of cystine and dibasic amino acids.

References

Solute carrier family {{membrane-protein-stub