Human Mpv17-like protein is localized in peroxisomes and regulates expression of antioxidant enzymes

Biochem Biophys Res Commun. 2006 Jun 9;344(3):948-54. doi: 10.1016/j.bbrc.2006.04.008. Epub 2006 Apr 19.


M-LP (Mpv17-like protein) is a protein that was initially identified in mouse tissues and shows high sequence homology with Mpv17 protein, a peroxisomal membrane protein involved in the development of early-onset glomerulosclerosis [R. Iida, T. Yasuda, E. Tsubota, H. Takatsuka, M. Masuyama, T. Matsuki, K. Kishi, M-LP, Mpv17-like protein, has a peroxisomal membrane targeting signal comprising a transmembrane domain and a positively charged loop and up-regulates expression of the manganese superoxide dismutase gene, J. Biol. Chem. 278 (2003) 6301-6306]. Here we report the identification and characterization of a human homolog of the M-LP (M-LPH) gene. The M-LPH gene is composed of four exons, extends over 14kb on chromosome 16p13.1, and is expressed as two alternatively spliced variants comprising four and three exons, respectively, which include open-reading frames encoding two distinct isoforms composed of 196 (M-LPH1) and 147 (M-LPH2) amino acids, respectively. These two variants were expressed ubiquitously in human tissues, however only M-LPH1 was detected at the protein level. Dual-color confocal analysis of COS-7 cells transfected with a green fluorescent protein-tagged M-LPH1 demonstrated that M-LPH1 is localized in peroxisomes. In order to elucidate the function of M-LPH1, we examined the mRNA levels of several enzymes involved in the metabolism of reactive oxygen species in COS-7 cells and found that transfection with M-LPH1 down-regulates expression of the plasma glutathione peroxidase and catalase genes. These results show the existence of the human homolog of M-LP and its participation in reactive oxygen species metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / metabolism*
  • COS Cells
  • Cells, Cultured
  • Chlorocebus aethiops
  • Enzymes / metabolism*
  • Gene Expression Regulation, Enzymologic / physiology*
  • Humans
  • Membrane Proteins / chemistry*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Peroxisomes / metabolism*
  • Reactive Oxygen Species / metabolism*
  • Sequence Homology, Amino Acid


  • Antioxidants
  • Enzymes
  • MPV17L protein, human
  • Membrane Proteins
  • Mpv17 protein, mouse
  • Reactive Oxygen Species