Thiamine transporter 2 (ThTr-2), also known as solute carrier family 19 member 3, is a protein that in humans is encoded by the SLC19A3gene.[1][2][3] SLC19A3 is a thiamine transporter.
Mutations in this gene cause biotin-responsive basal ganglia disease (BBGD); a recessive disorder manifested in childhood that progresses to chronic encephalopathy, dystonia, quadriparesis, and death if untreated. Patients with BBGD have bilateral necrosis in the head of the caudate nucleus and in the putamen. Administration of high doses of biotin in the early progression of the disorder eliminates pathological symptoms while delayed treatment results in residual paraparesis, mild mental retardation, or dystonia. Administration of thiamine is ineffective in the treatment of this disorder. Experiments have failed to show that this protein can transport biotin. Mutations in this gene also cause a Wernicke's-like encephalopathy.[1]
↑Eudy JD, Spiegelstein O, Barber RC, Wlodarczyk BJ, Talbot J, Finnell RH (December 2000). "Identification and characterization of the human and mouse SLC19A3 gene: a novel member of the reduced folate family of micronutrient transporter genes". Mol. Genet. Metab. 71 (4): 581–90. doi:10.1006/mgme.2000.3112. PMID11136550.
Subramanian VS, Marchant JS, Said HM (2006). "Biotin-responsive basal ganglia disease-linked mutations inhibit thiamine transport via hTHTR2: biotin is not a substrate for hTHTR2". Am. J. Physiol., Cell Physiol. 291 (5): C851–9. doi:10.1152/ajpcell.00105.2006. PMID16790503.
Nabokina SM, Said HM (2004). "Characterization of the 5'-regulatory region of the human thiamin transporter SLC19A3: in vitro and in vivo studies". Am. J. Physiol. Gastrointest. Liver Physiol. 287 (4): G822–9. doi:10.1152/ajpgi.00234.2004. PMID15217784.
Liu S, Stromberg A, Tai HH, Moscow JA (2004). "Thiamine transporter gene expression and exogenous thiamine modulate the expression of genes involved in drug and prostaglandin metabolism in breast cancer cells". Mol. Cancer Res. 2 (8): 477–87. PMID15328374.
Ganapathy V, Smith SB, Prasad PD (2004). "SLC19: the folate/thiamine transporter family". Pflügers Arch. 447 (5): 641–6. doi:10.1007/s00424-003-1068-1. PMID14770311.
Ashokkumar B, Vaziri ND, Said HM (2006). "Thiamin uptake by the human-derived renal epithelial (HEK-293) cells: cellular and molecular mechanisms". Am. J. Physiol. Renal Physiol. 291 (4): F796–805. doi:10.1152/ajprenal.00078.2006. PMID16705148.
Nabokina SM, Reidling JC, Said HM (2005). "Differentiation-dependent up-regulation of intestinal thiamin uptake: cellular and molecular mechanisms". J. Biol. Chem. 280 (38): 32676–82. doi:10.1074/jbc.M505243200. PMID16055442.
Rajgopal A, Edmondnson A, Goldman ID, Zhao R (2001). "SLC19A3 encodes a second thiamine transporter ThTr2". Biochim. Biophys. Acta. 1537 (3): 175–8. doi:10.1016/s0925-4439(01)00073-4. PMID11731220.
Liu X, Lam EK, Wang X, et al. (2009). "Promoter hypermethylation mediates downregulation of thiamine receptor SLC19A3 in gastric cancer". Tumour Biol. 30 (5–6): 242–8. doi:10.1159/000243767. PMID19816091.
Hillier LW, Graves TA, Fulton RS, et al. (2005). "Generation and annotation of the DNA sequences of human chromosomes 2 and 4". Nature. 434 (7034): 724–31. doi:10.1038/nature03466. PMID15815621.
Subramanian VS, Marchant JS, Said HM (2006). "Targeting and trafficking of the human thiamine transporter-2 in epithelial cells". J. Biol. Chem. 281 (8): 5233–45. doi:10.1074/jbc.M512765200. PMID16371350.
Liu S, Huang H, Lu X, et al. (2003). "Down-regulation of thiamine transporter THTR2 gene expression in breast cancer and its association with resistance to apoptosis". Mol. Cancer Res. 1 (9): 665–73. PMID12861052.
