Molecular cloning, functional characterization and genomic organization of four alternatively spliced isoforms of the human organic cation transporter 1 (hOCT1/SLC22A1)

Ann Hum Genet. 1999 Nov;63(Pt 6):473-82. doi: 10.1017/S0003480099007770.

Abstract

In this study we report the cloning of four human OCT1 (hOCT1/SLC22A1) isoforms: a long form, hOCT1G/L554, and three shorter forms (hOCT1G/L506, hOCT1G483 and hOCT1G353). All four variants could be identified in the human glioma cell line SK-MG-1, whereas only two isoforms (hOCT1G/L554 and hOCT1G/L506) were found in human liver cDNA. The hOCT1G/L554 represents the full length hOCT1 since the sequence of this clone is more than 99% identical to previously cloned hOCT1 cDNAs. Elucidation of the gene structure of human OCT1 demonstrated that the other isolated isoforms are alternatively spliced variants. The hOCT1 gene consists of 7 exons and 6 introns. When stably expressed in human embryonic kidney (HEK293) cells, only the full length hOCT1 cDNA mediated decynium-22 (D22)-sensitive uptake of tritiated 1-methyl-4-phenylpyridinium ([3H]-MPP+).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Methyl-4-phenylpyridinium / metabolism
  • Alternative Splicing
  • Amino Acid Sequence
  • Base Sequence
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism*
  • Cell Line
  • Cloning, Molecular
  • DNA Primers / genetics
  • DNA, Complementary / genetics
  • Exons
  • Gene Expression
  • Humans
  • Introns
  • Ion Transport
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Organic Cation Transporter 1
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Sequence Homology, Amino Acid
  • Transfection

Substances

  • Carrier Proteins
  • DNA Primers
  • DNA, Complementary
  • Membrane Proteins
  • Organic Cation Transporter 1
  • Protein Isoforms
  • 1-Methyl-4-phenylpyridinium