- Advanced search
Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).
Members of the choline transporter-like family are encoded by five genes (CTL1-CTL5) with further diversity occurring through alternative splicing of CTL1, 4 and 5 . CTL family members are putative 10TM domain proteins with extracellular termini that mediate Na+-independent transport of choline with an affinity that is intermediate to that of the high affinity choline transporter CHT1 (SLC5A7) and the low affinity organic-cation transporters [OCT1 (SLC22A1) and OCT2 (SLC22A2)] . CLT1 is expressed almost ubiquitously in human tissues  and mediates choline transport across the plasma and mitochondrial membranes . Transport of choline by CTL2, which in rodents is expressed as two isoforms (CTL2P1 and CLTP2; ) in lung, colon, inner ear and spleen and to a lesser extent in brain, tongue, liver, and kidney, has only recently been demonstrated [3,8]. CTL3-5 remain to be characterized functionally.
* Key recommended reading is highlighted with an asterisk
* Inazu M. (2014) Choline transporter-like proteins CTLs/SLC44 family as a novel molecular target for cancer therapy. Biopharm Drug Dispos, 35 (8): 431-49. [PMID:24532461]
* Lockman PR, Allen DD. (2002) The transport of choline. Drug Dev Ind Pharm, 28 (7): 749-71. [PMID:12236062]
* Michel V, Yuan Z, Ramsubir S, Bakovic M. (2006) Choline transport for phospholipid synthesis. Exp. Biol. Med. (Maywood), 231 (5): 490-504. [PMID:16636297]
* Traiffort E, O'Regan S, Ruat M. (2013) The choline transporter-like family SLC44: properties and roles in human diseases. Mol. Aspects Med., 34 (2-3): 646-54. [PMID:23506897]
1. Greinacher A, Wesche J, Hammer E, Fürll B, Völker U, Reil A, Bux J. (2010) Characterization of the human neutrophil alloantigen-3a. Nat. Med., 16 (1): 45-8. [PMID:20037594]
2. Inazu M, Takeda H, Matsumiya T. (2005) Molecular and functional characterization of an Na+-independent choline transporter in rat astrocytes. J. Neurochem., 94 (5): 1427-37. [PMID:16000150]
3. Kommareddi PK, Nair TS, Thang LV, Galano MM, Babu E, Ganapathy V, Kanazawa T, McHugh JB, Carey TE. (2010) Isoforms, expression, glycosylation, and tissue distribution of CTL2/SLC44A2. Protein J., 29 (6): 417-26. [PMID:20665236]
4. Kouji H, Inazu M, Yamada T, Tajima H, Aoki T, Matsumiya T. (2009) Molecular and functional characterization of choline transporter in human colon carcinoma HT-29 cells. Arch. Biochem. Biophys., 483 (1): 90-8. [PMID:19135976]
5. Michel V, Bakovic M. (2009) The solute carrier 44A1 is a mitochondrial protein and mediates choline transport. FASEB J., 23 (8): 2749-58. [PMID:19357133]
6. Michel V, Yuan Z, Ramsubir S, Bakovic M. (2006) Choline transport for phospholipid synthesis. Exp. Biol. Med. (Maywood), 231 (5): 490-504. [PMID:16636297]
7. Nair TS, Kozma KE, Hoefling NL, Kommareddi PK, Ueda Y, Gong TW, Lomax MI, Lansford CD, Telian SA, Satar B et al.. (2004) Identification and characterization of choline transporter-like protein 2, an inner ear glycoprotein of 68 and 72 kDa that is the target of antibody-induced hearing loss. J. Neurosci., 24 (7): 1772-9. [PMID:14973250]
8. Nakamura T, Fujiwara R, Ishiguro N, Oyabu M, Nakanishi T, Shirasaka Y, Maeda T, Tamai I. (2010) Involvement of choline transporter-like proteins, CTL1 and CTL2, in glucocorticoid-induced acceleration of phosphatidylcholine synthesis via increased choline uptake. Biol. Pharm. Bull., 33 (4): 691-6. [PMID:20410607]
9. Traiffort E, Ruat M, O'Regan S, Meunier FM. (2005) Molecular characterization of the family of choline transporter-like proteins and their splice variants. J. Neurochem., 92 (5): 1116-25. [PMID:15715662]
10. Uchida Y, Inazu M, Takeda H, Yamada T, Tajima H, Matsumiya T. (2009) Expression and functional characterization of choline transporter in human keratinocytes. J. Pharmacol. Sci., 109 (1): 102-9. [PMID:19122366]
11. Wille S, Szekeres A, Majdic O, Prager E, Staffler G, Stöckl J, Kunthalert D, Prieschl EE, Baumruker T, Burtscher H et al.. (2001) Characterization of CDw92 as a member of the choline transporter-like protein family regulated specifically on dendritic cells. J. Immunol., 167 (10): 5795-804. [PMID:11698453]
12. Yabuki M, Inazu M, Yamada T, Tajima H, Matsumiya T. (2009) Molecular and functional characterization of choline transporter in rat renal tubule epithelial NRK-52E cells. Arch. Biochem. Biophys., 485 (1): 88-96. [PMID:19236841]
13. Yamada T, Inazu M, Tajima H, Matsumiya T. (2011) Functional expression of choline transporter-like protein 1 (CTL1) in human neuroblastoma cells and its link to acetylcholine synthesis. Neurochem. Int., 58 (3): 354-65. [PMID:21185344]
Database page citation:
SLC44 choline transporter-like family. Accessed on 23/03/2017. IUPHAR/BPS Guide to PHARMACOLOGY, http://www.guidetopharmacology.org/GRAC/FamilyDisplayForward?familyId=233.
Concise Guide to PHARMACOLOGY citation:
Alexander SPH, Kelly E, Marrion N, Peters JA, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Southan C, Davies JA and CGTP Collaborators (2015) The Concise Guide to PHARMACOLOGY 2015/16: Transporters. Br J Pharmacol. 172: 6110-6202.