A third human carnitine/organic cation transporter (OCTN3) as a candidate for the 5q31 Crohn's disease locus (IBD5)

Biochem Biophys Res Commun. 2003 Jan 31;301(1):98-101. doi: 10.1016/s0006-291x(02)02946-7.


Organic cation transporters function primarily in the elimination of cationic drugs in kidney, intestine, and liver. The murine organic cation/carnitine (Octn) transporter family, Octn1, Octn2, and Octn3 is clustered on mouse chromosome 11 (NCBI Accession No. NW_000039). The human OCTN1 and OCTN2 orthologs map to the syntenic IBD5 locus at 5q31, which has been shown to confer susceptibility to Crohn's disease. We show that the human OCTN3 protein, whose corresponding gene is not yet cloned or annotated in the human reference DNA sequence, does indeed exist and is uniquely involved in carnitine-dependent transport in peroxisomes. Its functional properties and inferred chromosomal location implicate it for involvement in Crohn's disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport / physiology
  • Carnitine / metabolism
  • Cells, Cultured
  • Chromosomes, Human, Pair 5 / genetics*
  • Crohn Disease / genetics*
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Organic Cation Transport Proteins / genetics
  • Organic Cation Transport Proteins / metabolism*
  • Peroxisomes / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Tumor Cells, Cultured


  • Organic Cation Transport Proteins
  • Recombinant Fusion Proteins
  • Carnitine