Gene Symbol: Slc22a5
Description: solute carrier family 22 member 5
Alias: CT1, OCTN2, UST2r, solute carrier family 22 member 5, high-affinity carnitine transporter, high-affinity sodium-dependent carnitine cotransporter, integral membrane transport protein, organic cation/carnitine transporter 2, solute carrier family 22 (organic cation transporter), member 5, solute carrier family 22 (organic cation/carnitine transporter), member 5
Species: rat
Products:     Slc22a5

Top Publications

  1. Maeda T, Wakasawa T, Funabashi M, Fukushi A, Fujita M, Motojima K, et al. Regulation of Octn2 transporter (SLC22A5) by peroxisome proliferator activated receptor alpha. Biol Pharm Bull. 2008;31:1230-6 pubmed
    ..membrane for beta-oxidation, are well controlled by carnitine transporter organic cation/carnitine transporter 2 (OCTN2)...
  2. Tamai I, Ohashi R, Nezu J, Sai Y, Kobayashi D, Oku A, et al. Molecular and functional characterization of organic cation/carnitine transporter family in mice. J Biol Chem. 2000;275:40064-72 pubmed
    ..We have already shown that a defect of the organic cation/carnitine transporter OCTN2 is a primary cause of systemic carnitine deficiency...
  3. Ganapathy M, Huang W, Rajan D, Carter A, Sugawara M, Iseki K, et al. beta-lactam antibiotics as substrates for OCTN2, an organic cation/carnitine transporter. J Biol Chem. 2000;275:1699-707 pubmed
    ..b>OCTN2 is an organic cation/carnitine transporter that is responsible for Na(+)-coupled transport of carnitine in the ..
  4. Kato Y, Sai Y, Yoshida K, Watanabe C, Hirata T, Tsuji A. PDZK1 directly regulates the function of organic cation/carnitine transporter OCTN2. Mol Pharmacol. 2005;67:734-43 pubmed
    ..C-terminal proteins of OCTs and OCTNs identified a specific interaction of apical transporters OCTN1 and OCTN2, but not basolateral transporters OCT1 and OCT2, with PDZK1, intestinal and kidney-enriched PDZ protein, and Na+/H+..
  5. Luci S, Geissler S, König B, Koch A, Stangl G, Hirche F, et al. PPARalpha agonists up-regulate organic cation transporters in rat liver cells. Biochem Biophys Res Commun. 2006;350:704-8 pubmed
    ..We conclude that PPARalpha agonists increase carnitine concentrations in livers of rats and cells by an increased uptake of carnitine into the cell but not by an increased carnitine biosynthesis. ..
  6. Wu X, Prasad P, Leibach F, Ganapathy V. cDNA sequence, transport function, and genomic organization of human OCTN2, a new member of the organic cation transporter family. Biochem Biophys Res Commun. 1998;246:589-95 pubmed
    We have cloned OCTN2, a new member of the organic cation transporter family, from a human placental trophoblast cell line. The hOCTN2 cDNA codes for a protein of 557 amino acids with twelve putative transmembrane domains...
  7. Sekine T, Kusuhara H, Utsunomiya Tate N, Tsuda M, Sugiyama Y, Kanai Y, et al. Molecular cloning and characterization of high-affinity carnitine transporter from rat intestine. Biochem Biophys Res Commun. 1998;251:586-91 pubmed
    ..anion transporters and an organic cation transporter, we isolated a novel cDNA encoding a carnitine transporter (CT1) from rat intestine. CT1 encodes a 557-amino-acid protein with 12 putative membrane-spanning domains...
  8. Rodriguez C, Labus J, Hinton B. Organic cation/carnitine transporter, OCTN2, is differentially expressed in the adult rat epididymis. Biol Reprod. 2002;67:314-9 pubmed
    ..Recently, an organic cation transporter, OCTN2, was cloned from rat intestinal epithelium and shown to transport L-carnitine in a sodium-dependent manner...
  9. Nezu J, Tamai I, Oku A, Ohashi R, Yabuuchi H, Hashimoto N, et al. Primary systemic carnitine deficiency is caused by mutations in a gene encoding sodium ion-dependent carnitine transporter. Nat Genet. 1999;21:91-4 pubmed
    ..transport carnitine in a sodium-dependent manner prompted us to search for mutations in the gene encoding OCTN2, SLC22A5. Initially, we analysed the mouse gene and found a missense mutation in Slc22a5 in jvs mice...

More Information


  1. Tamai I, Ohashi R, Nezu J, Yabuuchi H, Oku A, Shimane M, et al. Molecular and functional identification of sodium ion-dependent, high affinity human carnitine transporter OCTN2. J Biol Chem. 1998;273:20378-82 pubmed
    ..In this study, we screened a human kidney cDNA library and assembled a cDNA-encoding OCTN2 as a homologue of the organic cation transporter OCTN1, and then we examined the function of OCTN2 as a carnitine ..
  2. Garrett Q, Xu S, Simmons P, Vehige J, Flanagan J, Willcox M. Expression and localization of carnitine/organic cation transporter OCTN1 and OCTN2 in ocular epithelium. Invest Ophthalmol Vis Sci. 2008;49:4844-9 pubmed publisher
    ..was conducted to determine the expression and localization of the carnitine/organic cation transporter (OCTN1 and OCTN2) in corneal or conjunctival epithelium...
  3. Maeda T, Goto A, Kobayashi D, Tamai I. Transport of organic cations across the blood-testis barrier. Mol Pharm. 2007;4:600-7 pubmed
    ..In addition, OCT1, OCT3, OCTN1, and OCTN2 were expressed in Sertoli cells...
  4. Ringseis R, Pösel S, Hirche F, Eder K. Treatment with pharmacological peroxisome proliferator-activated receptor alpha agonist clofibrate causes upregulation of organic cation transporter 2 in liver and small intestine of rats. Pharmacol Res. 2007;56:175-83 pubmed
    ..Relative mRNA concentration of OCTN2 in liver and small intestine was increased in rats fed clofibrate (P<0...
  5. Todesco L, Bur D, Brooks H, Torok M, Landmann L, Stieger B, et al. Pharmacological manipulation of L-carnitine transport into L6 cells with stable overexpression of human OCTN2. Cell Mol Life Sci. 2008;65:1596-608 pubmed publisher
    The high-affinity Na+-dependent carnitine transporter OCTN2 (SLC22A5) has a high renal expression and reabsorbs most filtered carnitine...
  6. Yoshimine K, Horiuchi M, Suzuki S, Kobayashi K, Abdul J, Masuda M, et al. Altered expression of atrial natriuretic peptide and contractile protein genes in hypertrophied ventricle of JVS mice with systemic carnitine deficiency. J Mol Cell Cardiol. 1997;29:571-8 pubmed
    ..These results suggest that the molecular characteristics of cardiac hypertrophy caused by carnitine deficiency are different from those of cardiac hypertrophy caused by aortic constriction. ..
  7. Kuwajima M, Lu K, Harashima H, Ono A, Sato I, Mizuno A, et al. Carnitine transport defect in fibroblasts of juvenile visceral steatosis (JVS) mouse. Biochem Biophys Res Commun. 1996;223:283-7 pubmed
    ..Thus there is hardly any carnitine transport activity in the fibroblasts of JVS mice, indicating that the JVS mouse can be regarded as an animal model of primary carnitine deficiency. ..
  8. Januszewicz E, Bekisz M, Mozrzymas J, Nałęcz K. High affinity carnitine transporters from OCTN family in neural cells. Neurochem Res. 2010;35:743-8 pubmed publisher
    ..Present study demonstrates expression of octn2 and octn3 genes coding high affinity carnitine transporters, as well as presence of both proteins in neurons ..
  9. Pochini L, Peta V, Indiveri C. Inhibition of the OCTN2 carnitine transporter by HgCl2 and methylmercury in the proteoliposome experimental model: insights in the mechanism of toxicity. Toxicol Mech Methods. 2013;23:68-76 pubmed publisher
    ..method has been used as a useful approach to test the effect of HgCl(2) and methylmercury (MeHg) on the carnitine (OCTN2) transporter...
  10. Tachikawa M, Takeda Y, Tomi M, Hosoya K. Involvement of OCTN2 in the transport of acetyl-L-carnitine across the inner blood-retinal barrier. Invest Ophthalmol Vis Sci. 2010;51:430-6 pubmed publisher
    ..These transport properties are consistent with those of carnitine transport by OCTN2. OCTN2 was predominantly expressed in TR-iBRB2 cells and isolated rat retinal vascular endothelial cells...
  11. Broderick T, El Midaoui A, Chiasson J, Wang D, Jankowski M, Gutkowska J. The effects of exercise training on ?-butyrobetaine hydroxylase and novel organic cation transporter-2 gene expression in the rat. Appl Physiol Nutr Metab. 2011;36:781-9 pubmed publisher
    ..The organic cation transporter (OCTN2), the carnitine transporter found in kidney, is important in the distribution of carnitine by facilitating its ..
  12. Friedrich A, Prasad P, Freyer D, Ganapathy V, Brust P. Molecular cloning and functional characterization of the OCTN2 transporter at the RBE4 cells, an in vitro model of the blood-brain barrier. Brain Res. 2003;968:69-79 pubmed
    ..acid), a compound known to be transported by the organic cation transporter/carnitine transporter OCTN2, was studied in immortalized rat brain endothelial cells (RBE4)...
  13. Karlic H, Lohninger A, Laschan C, Lapin A, Böhmer F, Huemer M, et al. Downregulation of carnitine acyltransferases and organic cation transporter OCTN2 in mononuclear cells in healthy elderly and patients with myelodysplastic syndromes. J Mol Med (Berl). 2003;81:435-42 pubmed
    ..palmitoyltransferases (CPT1 and CPT2), carnitine acetyltransferase (CRAT), human specific microsomal CPT, and OCTN2 (organic cation transporter) in mononuclear cells of healthy humans of different age groups and MDS patients...
  14. Li D, Liu J, Du W, Liu H, Xiao W, Song X, et al. Carnitine/organic cation transporter 2 (OCTN2) contributes to rat epididymal epithelial cell growth and proliferation. Biomed Pharmacother. 2017;93:444-450 pubmed publisher
    Carnitine/organic cation transporter 2 (OCTN2) is localized at the basolateral membrane of epididymal epithelial cells, and mainly serves to reabsorb carnitine as an essential factor for sperm maturation; however, its functional features ..
  15. Ohnishi S, Okamura N, Sakamoto S, Hasegawa H, Norikura R, Kanaoka E, et al. Role of Na+/L-carnitine transporter (OCTN2) in renal handling of pivaloylcarnitine and valproylcarnitine formed during pivalic acid-containing prodrugs and valproic acid treatment. Drug Metab Pharmacokinet. 2008;23:293-303 pubmed
    ..response, we investigated the renal handling of these acylcarnitines by Na+/L-carnitine cotransporter, OCTN2 using the isolated perfused rat kidney, rat OCTN2 (rOCTN2) and human OCTN2 (hOCTN2) expressing cells...
  16. Furuichi Y, Sugiura T, Kato Y, Shimada Y, Masuda K. OCTN2 is associated with carnitine transport capacity of rat skeletal muscles. Acta Physiol (Oxf). 2010;200:57-64 pubmed publisher
    ..b>OCTN2, a sodium-dependent solute carrier, is assumed to transport carnitine into various organs...
  17. Lahjouji K, Elimrani I, Lafond J, Leduc L, Qureshi I, Mitchell G. L-Carnitine transport in human placental brush-border membranes is mediated by the sodium-dependent organic cation transporter OCTN2. Am J Physiol Cell Physiol. 2004;287:C263-9 pubmed
    ..Western blot analysis revealed that OCTN2, a high-affinity, Na(+)-dependent carnitine transporter, was present in placental BBM but not in isolated basal ..
  18. Matsuishi T, Hirata K, Terasawa K, Kato H, Yoshino M, Ohtaki E, et al. Successful carnitine treatment in two siblings having lipid storage myopathy with hypertrophic cardiomyopathy. Neuropediatrics. 1985;16:6-12 pubmed
    ..Carnitine was decreased in the skeletal muscles and the serum. Treatment with DL-carnitine to both cases resulted in marked clinical improvement and decreased lipid droplets in the muscles. ..
  19. Fujiya M, Musch M, Nakagawa Y, Hu S, Alverdy J, Kohgo Y, et al. The Bacillus subtilis quorum-sensing molecule CSF contributes to intestinal homeostasis via OCTN2, a host cell membrane transporter. Cell Host Microbe. 2007;1:299-308 pubmed
    ..These effects of CSF depend on its uptake by an apical membrane organic cation transporter-2 (OCTN2)...
  20. Glube N, Closs E, Langguth P. OCTN2-mediated carnitine uptake in a newly discovered human proximal tubule cell line (Caki-1). Mol Pharm. 2007;4:160-8 pubmed
    ..Objectives of this study include the characterization of OCTN2 function in the Caki-1 cell line and the potential interactions of carnitine uptake with renally secreted drugs, ..
  21. Shekhawat P, Yang H, Bennett M, Carter A, Matern D, Tamai I, et al. Carnitine content and expression of mitochondrial beta-oxidation enzymes in placentas of wild-type (OCTN2(+/+)) and OCTN2 Null (OCTN2(-/-)) Mice. Pediatr Res. 2004;56:323-8 pubmed
    ..the role of carnitine in the expression of the enzymes involved in fatty acid beta-oxidation in placenta of OCTN2(-/-) mice with defective carnitine transporter (OCTN2)...
  22. Rahbeeni Z, Vaz F, al Hussein K, Bucknall M, Ruiter J, Wanders R, et al. Identification of two novel mutations in OCTN2 from two Saudi patients with systemic carnitine deficiency. J Inherit Metab Dis. 2002;25:363-9 pubmed
    ..Recently, a human gene, SLC22A5, encoding a sodium-dependent high-affinity carnitine transporter OCTN2 was cloned from human kidney and shown to ..
  23. Kuwajima M, Kono N, Horiuchi M, Imamura Y, Ono A, Inui Y, et al. Animal model of systemic carnitine deficiency: analysis in C3H-H-2 degrees strain of mouse associated with juvenile visceral steatosis. Biochem Biophys Res Commun. 1991;174:1090-4 pubmed
    ..This is a useful animal model to analyze the role of carnitine in lipid, amino acid and carbohydrate metabolism. ..
  24. Kobayashi D, Irokawa M, Maeda T, Tsuji A, Tamai I. Carnitine/organic cation transporter OCTN2-mediated transport of carnitine in primary-cultured epididymal epithelial cells. Reproduction. 2005;130:931-7 pubmed
    ..uptake of carnitine by the cells was significantly reduced by inhibitors of carnitine/organic cation transporter (OCTN2), such as carnitine analogues and cationic compounds. In RT-PCR analysis, OCTN2 expression was detected...
  25. Peltekova V, Wintle R, Rubin L, Amos C, Huang Q, Gu X, et al. Functional variants of OCTN cation transporter genes are associated with Crohn disease. Nat Genet. 2004;36:471-5 pubmed cation transporter cluster at 5q31 (a missense substitution in SLC22A4 and a G-->C transversion in the SLC22A5 promoter) form a haplotype associated with susceptibility to Crohn disease...
  26. Tomomura M, Imamura Y, Tomomura A, Horiuchi M, Saheki T. Abnormal gene expression and regulation in the liver of jvs mice with systemic carnitine deficiency. Biochim Biophys Acta. 1994;1226:307-14 pubmed
    ..We suggest that elevated AP-1 binding induced by carnitine deficiency is closely connected with the abnormal gene expression in the liver. ..
  27. Cano M, Calonge M, Ilundain A. Expression of OCTN2 and OCTN3 in the apical membrane of rat renal cortex and medulla. J Cell Physiol. 2010;223:451-9 pubmed publisher apical membrane vesicles revealed that the apical membrane of rat kidney cortex and medulla presents OCTN2 and OCTN3 proteins and transports L-[(3)H]-carnitine in a Na(+)-dependent and -independent manner...
  28. D Argenio G, Calvani M, Casamassimi A, Petillo O, Margarucci S, Rienzo M, et al. Experimental colitis: decreased Octn2 and Atb0+ expression in rat colonocytes induces carnitine depletion that is reversible by carnitine-loaded liposomes. FASEB J. 2006;20:2544-6 pubmed
    ..We investigated this issue by examining the expression of the carnitine transporters OCTN2 and ATB0+, and butyrate metabolism in colonocytes in a rat model of IBD induced by trinitrobenzene sulfonic acid (..
  29. Schomig E, Spitzenberger F, Engelhardt M, Martel F, Ording N, Gründemann D. Molecular cloning and characterization of two novel transport proteins from rat kidney. FEBS Lett. 1998;425:79-86 pubmed
    ..Characteristic signatures for the ASF family were identified. ..
  30. García Delgado M, Peral M, Duran J, García Miranda P, Calonge M, Ilundáin A. Ontogeny of Na(+)/L-carnitine transporter and of gamma-trimethylaminobutyraldehyde dehydrogenase and gamma-butyrobetaine hydroxylase genes expression in rat kidney. Mech Ageing Dev. 2009;130:227-33 pubmed publisher
    The kidney synthesizes L-carnitine and reabsorbs it via the Na(+)/L-carnitine cotransporter OCTN2. This study investigates the ontogeny of OCTN2, gamma-trimethylaminobutyraldehyde dehydrogenase (TMABA-DH) and gamma-butyrobetaine ..
  31. Kobayashi D, Goto A, Maeda T, Nezu J, Tsuji A, Tamai I. OCTN2-mediated transport of carnitine in isolated Sertoli cells. Reproduction. 2005;129:729-36 pubmed
    ..In RT-PCR analysis, the high-affinity carnitine transporter OCTN2 was detected in rat whole testis tissue and primary-cultured Sertoli cells...
  32. Czeredys M, Samluk Ł, Michalec K, Tułodziecka K, Skowronek K, Nałęcz K. Caveolin-1--a novel interacting partner of organic cation/carnitine transporter (Octn2): effect of protein kinase C on this interaction in rat astrocytes. PLoS ONE. 2013;8:e82105 pubmed publisher
    OCTN2--the Organic Cation Transporter Novel family member 2 (SLC22A5) is known to be a xenobiotic/drug transporter...
  33. Miecz D, Januszewicz E, Czeredys M, Hinton B, Berezowski V, Cecchelli R, et al. Localization of organic cation/carnitine transporter (OCTN2) in cells forming the blood-brain barrier. J Neurochem. 2008;104:113-23 pubmed
    ..Therefore more detailed experiments were performed on expression and localization of a high affinity carnitine transporter OCTN2 in an in vitro model of the blood-brain barrier by real-time PCR, western blot analysis, and ..
  34. Yokogawa K, Yonekawa M, Tamai I, Ohashi R, Tatsumi Y, Higashi Y, et al. Loss of wild-type carrier-mediated L-carnitine transport activity in hepatocytes of juvenile visceral steatosis mice. Hepatology. 1999;30:997-1001 pubmed
    ..The hepatic carnitine transport properties in wild-type hepatocytes were similar to those of high-affinity mouse Octn2-transfected HEK293 cells...
  35. Hashimoto N, Suzuki F, Tamai I, Nikaido H, Kuwajima M, Hayakawa J, et al. Gene-dose effect on carnitine transport activity in embryonic fibroblasts of JVS mice as a model of human carnitine transporter deficiency. Biochem Pharmacol. 1998;55:1729-32 pubmed
    ..Similar phenomena have been observed in human primary carnitine deficiency. Therefore, JVS mice may be useful for understanding this extremely rare human hereditary disorder. ..
  36. Wu X, Huang W, Prasad P, Seth P, Rajan D, Leibach F, et al. Functional characteristics and tissue distribution pattern of organic cation transporter 2 (OCTN2), an organic cation/carnitine transporter. J Pharmacol Exp Ther. 1999;290:1482-92 pubmed
    ..b>OCTN2 transports organic cations without involving Na(+), but it transports carnitine only in the presence of Na(+)...
  37. Horiuchi M, Kobayashi K, Yamaguchi S, Shimizu N, Koizumi T, Nikaido H, et al. Primary defect of juvenile visceral steatosis (jvs) mouse with systemic carnitine deficiency is probably in renal carnitine transport system. Biochim Biophys Acta. 1994;1226:25-30 pubmed
    ..These results indicate that the primary defect of jvs mice is most probably related to the system for reabsorption of carnitine in the kidney. ..
  38. Furuichi Y, Sugiura T, Kato Y, Takakura H, Hanai Y, Hashimoto T, et al. Muscle contraction increases carnitine uptake via translocation of OCTN2. Biochem Biophys Res Commun. 2012;418:774-9 pubmed publisher
    ..OCTN2 (SLC22A5), a sodium-dependent solute carrier, is assumed to transport carnitine into skeletal muscle cells...
  39. Yokogawa K, Higashi Y, Tamai I, Nomura M, Hashimoto N, Nikaido H, et al. Decreased tissue distribution of L-carnitine in juvenile visceral steatosis mice. J Pharmacol Exp Ther. 1999;289:224-30 pubmed
    ..The JVS mouse should be a useful experimental model for studying carnitine deficiency diseases. ..
  40. Toshimori K, Kuwajima M, Yoshinaga K, Wakayama T, Shima K. Dysfunctions of the epididymis as a result of primary carnitine deficiency in juvenile visceral steatosis mice. FEBS Lett. 1999;446:323-6 pubmed
    ..In contrast, the duct of the distal epididymis was constricted and contained no spermatozoa. Thus, the epididymal disorder causes obstructive azoospermia, leading to infertility. ..
  41. Horiuchi M, Yoshida H, Kobayashi K, Kuriwaki K, Yoshimine K, Tomomura M, et al. Cardiac hypertrophy in juvenile visceral steatosis (jvs) mice with systemic carnitine deficiency. FEBS Lett. 1993;326:267-71 pubmed
    ..The discovery of cardiac hypertrophy in carnitine-deficient jvs mice will lead to clarification of the pathophysiology of cardiomyopathy in systemic carnitine deficiency in human beings. ..
  42. Miyagawa J, Kuwajima M, Hanafusa T, Ozaki K, Fujimura H, Ono A, et al. Mitochondrial abnormalities of muscle tissue in mice with juvenile visceral steatosis associated with systemic carnitine deficiency. Virchows Arch. 1995;426:271-9 pubmed
    ..These results indicate that this murine strain associated with systemic carnitine deficiency exhibits a generalized mitochondrial abnormality in the muscle system especially in the heart. ..
  43. Li M, Yoshida G, Horiuchi M, Kobayashi K, Saheki T. Prolonged effect of single carnitine administration on fasted carnitine-deficient JVS mice regarding their locomotor activity and energy expenditure. Biochim Biophys Acta. 2006;1761:1191-9 pubmed
    ..These results suggest that the low tissue carnitine levels are therefore not the sole rate-limiting factor of general fatty acid oxidation in carnitine-deficient jvs(-/-) mice. ..
  44. Ling B, Alcorn J. LPS-induced inflammation downregulates mammary gland glucose, fatty acid, and L-carnitine transporter expression at different lactation stages. Res Vet Sci. 2010;89:200-2 pubmed publisher
    ..Glut1, Glut8 and Sglt1, fatty acid transporters Fatp1, Fatp4 and Fabp3, and L-carnitine transporters Octn1, Octn2, and Octn3 were determined using the Comparative C(T) method...
  45. Melegh B, Bene J, Mogyorosy G, Havasi V, Komlosi K, Pajor L, et al. Phenotypic manifestations of the OCTN2 V295X mutation: sudden infant death and carnitine-responsive cardiomyopathy in Roma families. Am J Med Genet A. 2004;131:121-6 pubmed
    ..with cardiomyopathy and decreased plasma carnitine levels, we identified homozygous deletion of 17081C of the SLC22A5 gene that results in a frameshift at R282D and leads ultimately to a premature stop codon (V295X) in the OCTN2 ..