Absolute levels of transcripts for mitochondrial uncoupling proteins UCP2, UCP3, UCP4, and UCP5 show different patterns in rat and mice tissues

J Bioenerg Biomembr. 2009 Feb;41(1):71-8. doi: 10.1007/s10863-009-9201-2. Epub 2009 Feb 26.


Existing controversies led us to analyze absolute mRNA levels of mitochondrial uncoupling proteins (UCP1-UCP5). Individual UCP isoform mRNA levels varied by up to four orders of magnitude in rat and mouse tissues. UCP2 mRNA content was relatively high (0.4 to 0.8 pg per 10 ng of total mRNA) in rat spleen, rat and mouse lung, and rat heart. Levels of the same order of magnitude were found for UCP3 mRNA in rat and mouse skeletal muscle, for UCP4 and UCP5 mRNA in mouse brain, and for UCP2 and UCP5 mRNA in mouse white adipose tissue. Significant differences in pattern were found for rat vs. mouse tissues, such as the dominance of UCP3/UCP5 vs. UCP2 transcript in mouse heart and vice versa in rat heart; or UCP2 (UCP5) dominance in rat brain contrary to 10-fold higher UCP4 and UCP5 dominance in mouse brain. We predict high antioxidant/antiapoptotic UCP function in tissues with higher UCP mRNA content.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / metabolism
  • DNA Primers / genetics
  • Ion Channels / metabolism*
  • Lung / metabolism
  • Membrane Transport Proteins / metabolism*
  • Mice
  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Proteins / metabolism*
  • Mitochondrial Uncoupling Proteins
  • Myocardium / metabolism
  • Nerve Tissue Proteins / metabolism*
  • RNA, Messenger / metabolism*
  • Rats
  • Reverse Transcriptase Polymerase Chain Reaction
  • Species Specificity
  • Spleen / metabolism
  • Uncoupling Protein 2
  • Uncoupling Protein 3


  • DNA Primers
  • Ion Channels
  • Membrane Transport Proteins
  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Proteins
  • Mitochondrial Uncoupling Proteins
  • Nerve Tissue Proteins
  • RNA, Messenger
  • Slc25a14 protein, rat
  • Slc25a27 protein, rat
  • Ucp2 protein, mouse
  • Ucp2 protein, rat
  • Ucp3 protein, mouse
  • Ucp3 protein, rat
  • Uncoupling Protein 2
  • Uncoupling Protein 3