CTNS

This gene encodes a seven-transmembrane domain protein that functions to transport cystine out of lysosomes. Its activity is driven by the H+ electrochemical gradient of the lysosomal membrane. Mutations in this gene cause cystinosis, a lysosomal storage disorder. Alternative splicing results in multiple transcript variants. [provided by RefSeq]

cystinosis, nephropathic

Cystine/H+ symporter that mediates export of cystine, the oxidized dimer of cysteine, from lysosomes (PubMed:11689434, PubMed:18337546, PubMed:22232659, PubMed:29467429, PubMed:33208952, PubMed:15128704).

Plays an important role in melanin synthesis by catalyzing cystine export from melanosomes, possibly by inhibiting pheomelanin synthesis (PubMed:22649030).

In addition to cystine export, also acts as a positive regulator of mTORC1 signaling in kidney proximal tubular cells, via interactions with components of the v-ATPase and Ragulator complexes (By similarity).

Also involved in small GTPase-regulated vesicle trafficking and lysosomal localization of LAMP2A, independently of cystine transporter activity (By similarity).

Adult walking behavior Source: Ensembl
ATP metabolic process Source: UniProtKB
Brain development Source: UniProtKB
Cellular amino acid metabolic process Source: UniProtKB
Cognition Source: UniProtKB
Glutathione metabolic process Source: UniProtKB
Grooming behavior Source: Ensembl
Ion transport Source: Reactome
L-cystine transport Source: UniProtKB
Lens development in camera-type eye Source: Ensembl
Long-term memory Source: Ensembl
Melanin biosynthetic process Source: UniProtKB-KW
Negative regulation of hydrogen peroxide biosynthetic process Source: Ensembl
Positive regulation of mitochondrial membrane potential Source: Ensembl
Positive regulation of TORC1 signaling Source: Ensembl
Protein transport Source: UniProtKB-KW
Regulation of melanin biosynthetic process Source: UniProtKB
Transmembrane transport Source: Reactome
Visual learning Source: Ensembl

Isoform 1: Lysosome membrane; Melanosome membrane. AP-3 complex is required for localization to the lysosome.
Isoform 2: Lysosome membrane; Cell membrane

Cystinosis, nephropathic type (CTNS):
A form of cystinosis, a lysosomal storage disease due to defective transport of cystine across the lysosomal membrane. This results in cystine accumulation and crystallization in the cells causing widespread tissue damage. The classical nephropathic form has onset in the first year of life and is characterized by a polyuro-polydipsic syndrome, marked height-weight growth delay, generalized impaired proximal tubular reabsorptive capacity, with severe fluid-electrolyte balance alterations, renal failure, ocular symptoms and other systemic complications.
Cystinosis, adult, non-nephropathic type (CTNSANN):
A form of cystinosis, a lysosomal storage disease due to defective transport of cystine across the lysosomal membrane. This results in cystine accumulation and crystallization in the cells causing widespread tissue damage. Cystinosis adult non-nephropathic type is characterized by ocular features and a benign course. Patients manifest mild photophobia due to conjunctival and corneal cystine crystals.
Cystinosis, late-onset juvenile or adolescent nephropathic type (CTNSJAN):
A form of cystinosis, a lysosomal storage disease due to defective transport of cystine across the lysosomal membrane. This results in cystine accumulation and crystallization in the cells causing widespread tissue damage. Late-onset juvenile or adolescent nephropathic cystinosis is an intermediated form, manifesting first at age 10 to 12 years with proteinuria due to glomerular damage rather than with the manifestations of tubular damage that occur first in infantile cystinosis. There is no excess amino aciduria and stature is normal. Photophobia, late development of pigmentary retinopathy, and chronic headaches are features.

Lumenal: 23-121
Helical: 122-142
Cytoplasmic: 143-161
Helical: 162-182
Lumenal: 183-205
Helical: 206-226
Cytoplasmic: 227-237
Helical: 238-258
Lumenal: 259-261
Helical: 262-282
Cytoplasmic: 283-297
Helical: 298-318
Lumenal: 319-335
Helical: 336-356
Cytoplasmic: 357-367