Reactome | CTNS cotransports CySS-, H+ from lysosomal lumen to cytosol

CTNS cotransports CySS-, H+ from lysosomal lumen to cytosol

Stable Identifier

R-HSA-5340130

Type

Reaction [transition]

Species

Homo sapiens

Compartment

cytosol, lysosomal lumen, lysosomal membrane

ReviewStatus

5/5

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CTNS cotransports CySS-, H+ from lysosomal lumen to cytosol

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Cystinosin (CTNS) is an integral lysosomal membrane protein which can transport L-cystine (CySS-, the oxidative product of two cysteine molecules linked via a disulfide bond) together with H+ out of lysosomes. CySS- is a component of hair, skin and nails. Defects in CTNS cause cystinosis, lysosomal storage-type diseases due to defective transport of CySS- across the lysosomal membrane (Town et al. 1998, Anikster et al. 1999; review Elmonem et al. 2016). Patients with cystinosis frequently exhibit blond hair and a fair complexion, suggesting an involvement in melanogenesis. Chiaverini et al. show CTNS is also localised to melanosomes. CTNS silencing led to a 75% reduction of melanin synthesis, caused by a degradation of tyrosinase (the enzyme responsible for melanin biosynthesis), thereby identifying a role for CTNS in melanogenesis (Chiaverini et al. 2012).

Literature References

PubMed ID	Title	Journal	Year
27102039	Cystinosis: a review Veys, KR, van den Heuvel, LP, Levtchenko, E, Soliman, NA, van Dyck, M, Elmonem, MA	Orphanet J Rare Dis	2016
10571941	CTNS mutations in patients with cystinosis Anikster, Y, Shotelersuk, V, Gahl, WA	Hum. Mutat.	1999
9537412	A novel gene encoding an integral membrane protein is mutated in nephropathic cystinosis Attard, M, Bates, GP, Whitmore, SA, Cherqui, S, Callen, DF, van't Hoff, W, Town, M, Gribouval, O, Jean, G, Antignac, C, Broyer, M, Forestier, L	Nat. Genet.	1998
22649030	Cystinosin is a melanosomal protein that regulates melanin synthesis Picardo, M, Flori, E, Berard, E, Antignac, C, Cochat, P, Fontas, E, Bernard, FX, Sillard, L, Guest, G, Ortonne, JP, Briganti, S, Wakamatsu, K, Cailliez, M, Chiaverini, C, Foulard, M, Ito, S, Ballotti, R, Niaudet, P	FASEB J.	2012