Acts as a chaperone that facilitates biogenesis and trafficking of functional transporter heteromers to the plasma membrane (By similarity) (PubMed:10588648, PubMed:11318953, PubMed:16609684, PubMed:16825196, PubMed:32494597, PubMed:32817565, PubMed:7686906, PubMed:8486766, PubMed:8663184, PubMed:8663357). Associates with SLC7A9 to form a functional transporter complex that mediates the electrogenic exchange between cationic amino acids and neutral amino acids, with a stoichiometry of 1:1. SLC7A

Cell membraneApical cell membrane

Cystinuria

An autosomal disorder characterized by impaired epithelial cell transport of cystine and dibasic amino acids (lysine, ornithine, and arginine) in the proximal renal tubule and gastrointestinal tract. The impaired renal reabsorption of cystine and its low solubility causes the formation of calculi in the urinary tract, resulting in obstructive uropathy, pyelonephritis, and, rarely, renal failure.

Serine peptidase whose precise substrate specificity remains unclear (PubMed:16143824, PubMed:16385448, PubMed:28726805). Does not cleave peptides after a arginine or lysine residue (PubMed:16143824). Regulates trans-Golgi network morphology and sorting by regulating the membrane binding of the AP-1 complex (PubMed:23321636). May play a role in the regulation of synaptic vesicle exocytosis (PubMed:24610330)

Cytoplasm, cytosolGolgi apparatus, trans-Golgi networkCytoplasm, cytoskeletonGolgi apparatusNucleus

Hypotonia-cystinuria syndrome

Characterized generalized hypotonia at birth, nephrolithiasis, growth hormone deficiency, minor facial dysmorphism, failure to thrive, followed by hyperphagia and rapid weight gain in late childhood.

Catalyzes the trimethylation of 'Lys-116' in calmodulin

CytoplasmNucleusGolgi apparatus

Hypotonia-cystinuria syndrome

Characterized generalized hypotonia at birth, nephrolithiasis, growth hormone deficiency, minor facial dysmorphism, failure to thrive, followed by hyperphagia and rapid weight gain in late childhood.