title: Distribution of cystinosin-LKG in human tissues.
abstract: Nephropathic cystinosis is multisystemic progressive disorder caused by mutations of CTNS gene that encodes for the lysosomal cystine co-transporter cystinosin, and for a less abundant isoform termed cystinosin-LKG, which is expressed in not only lysosomes but also other cell compartments. To overcome the absence of high-quality antibodies against cystinosin, we have obtained a rabbit antiserum against cystinosin-LKG and have analyzed in human tissues the expression of the two known cystinosin isoforms by RT-PCR, and the expression of cystinosin-LKG by immunohistochemistry. In most tissues, CTNS-LKG represents 5-20 % of CTNS transcripts, with the exception of the testis that expresses both isoforms in equal proportions. Cystinosin-LKG was found to be highly expressed in renal tubular cells, pancreatic islets of Langerhans, Leydig cells of the testis, mucoserous glands of the bronchial wall, melanocytes and keratinocytes. These results are parallel with many features of cystinosis, such as early onset Fanconi syndrome, male infertility, diabetes mellitus and hypopigmentation. Intermediate expression levels were of the LKG isoform observed in the gastro-intestinal tract and thyroid glands; low levels of expression were observed in the brain, skeletal and cardiac muscles.
authors.affiliation: Division of Nephrology, Department of Nephrology and Urology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. anna.taranta@opbg.net
authors.forename: Anna
authors.initials: A
authors.lastname: Taranta
authors.forename: Stefania
authors.initials: S
authors.lastname: Petrini
authors.forename: Arianna
authors.initials: A
authors.lastname: Citti
authors.forename: Renata
authors.initials: R
authors.lastname: Boldrini
authors.forename: Serena
authors.initials: S
authors.lastname: Corallini
authors.forename: Francesco
authors.initials: F
authors.lastname: Bellomo
authors.forename: Elena
authors.initials: E
authors.lastname: Levtchenko
authors.forename: Francesco
authors.initials: F
authors.lastname: Emma
mesh_terms: D026921:Amino Acid Transport Systems, Neutral / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D003554:Cystinosis / Q000235:genetics / Q000378:metabolism; D004285:Dogs; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D009928:Organ Specificity; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism
chemical_list: D026921:Amino Acid Transport Systems, Neutral; C111445:CTNS protein, human; D020033:Protein Isoforms