Mouse MCT3 gene is expressed preferentially in retinal pigment and choroid plexus epithelia

Am J Physiol Cell Physiol. 2001 May;280(5):C1319-26. doi: 10.1152/ajpcell.2001.280.5.C1319.


Monocarboxylate transporters (MCTs) are a family of highly homologous membrane proteins that mediate the 1:1 transport of a proton and a lactate ion. In chicken, MCT3 is preferentially expressed in the retinal pigment epithelium (RPE). We have isolated the mouse MCT3 cDNA and gene and characterized the pattern of tissue expression. MCT3 is a single copy gene with a 1.8-kb transcript that encodes a protein with a predicted molecular mass of 51.5 kDa. Based on Northern hybridization analysis, MCT3 transcript was expressed in only two tissues: RPE and choroid plexus epithelium (CPE). The choroid plexus forms a barrier between the cerebrospinal fluid and fenestrated capillaries, similar to the organization of the RPE and choroidal vessels. Immunohistochemical staining demonstrated that MCT3 was restricted to the basolateral membranes of both epithelia but was more abundant in RPE than CPE. Differences in the level of protein expression were confirmed by Western blot analysis. The cloning of MCT3 identifies a specific transporter that could regulate lactate levels in fluid-bathing neuronal tissues.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 5' Untranslated Regions / genetics
  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Carrier Proteins / analysis
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics*
  • Cell Membrane / metabolism
  • Chickens
  • Choroid Plexus / cytology
  • Choroid Plexus / physiology*
  • Cloning, Molecular
  • DNA, Complementary
  • Epithelial Cells / cytology
  • Epithelial Cells / physiology*
  • Exons
  • Humans
  • Introns
  • Membrane Transport Proteins*
  • Mice
  • Molecular Sequence Data
  • Molecular Weight
  • Monocarboxylic Acid Transporters
  • Organ Specificity
  • Pigment Epithelium of Eye / cytology
  • Pigment Epithelium of Eye / physiology*
  • RNA, Messenger / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Symporters
  • Transcription, Genetic*


  • 5' Untranslated Regions
  • Carrier Proteins
  • DNA, Complementary
  • Membrane Transport Proteins
  • Monocarboxylic Acid Transporters
  • RNA, Messenger
  • SLC16A3 protein, human
  • Slc16a3 protein, mouse
  • Symporters