• Source: DJ-1

      • DJ1, also known as Parkinson disease protein 7, is a protein which in humans is encoded by the PARK7 gene. Its weak glyoxalase activity has been verified by many labs, however the reported protein deglycase activity is likely to be an artifact stemming from DJ-1's ability to destroy free methylglyoxal.


      Structure




      = Gene

      =

      The gene PARK7, also known as DJ-1, encodes a protein of the peptidase C56 family. The human gene PARK7 has 8 exons and locates at chromosome band 1p36.23.


      = Protein

      =
      The human protein deglycase DJ-1 is 20 kDa in size and composed of 189 amino acids with seven β-strands and nine α-helices in total and is present as a dimer. It belongs to the peptidase C56 family of proteins.
      The protein structures of human protein DJ-1, Escherichia coli chaperone Hsp31, YhbO, and YajL and an Archaea protease are evolutionarily conserved.


      Function


      Under an oxidative condition, protein deglycase DJ-1 inhibits the aggregation of α-synuclein via its chaperone activity, thus functioning as a redox-sensitive chaperone and as a sensor for oxidative stress. Accordingly, DJ-1 apparently protects neurons against oxidative stress and cell death. In parallel, protein DJ-1 acts as a positive regulator of androgen receptor-dependent transcription. DJ-1 is expressed in both the neural retina and retinal pigment epithelium of mammals, where it exerts a neuroprotective role against oxidative stress under both physiological and pathological conditions.
      Pyrroloquinoline quinone (PQQ) has been shown to reduce the self-oxidation of the DJ-1 protein, an early step in the onset of some forms of Parkinson's disease.
      Functional DJ-1 protein has been shown to bind metals and protect against metal-induced cytotoxicity from copper and mercury.
      DJ-1/PARK7 and its bacterial homologs: Hsp31, YhbO, and YajL can repair methylglyoxal and glyoxal glycated nucleotides. Guanine, either in the form of a free nucleotide or as a nucleotide incorporated into nucleic acid (DNA or RNA), if glycated, can be repaired by DJ-1/PARK7. Deglycase-deficient bacterial mutants with reduced ability to repair glycated bases in DNA show strong mutator phenotypes.


      = DNA repair

      =
      DJ-1 is a DNA damage response protein that is recruited to sites of DNA damage where it participates in the repair of DNA double-strand breaks through the processes of non-homologous end joining and homologous recombination. Evidence for a linkage between DNA damage and Parkinson's disease has been reported for decades. Recently evidence has been presented that defective DNA repair is linked specifically to DJ-1 mutation, and thus DJ-1 mutation likely contributes to Parkinson's disease pathogenesis.


      Clinical significance


      Defects in this gene are the cause of autosomal recessive early-onset Parkinson's disease 7.


      Interactions


      PARK7 has been shown to interact with:

      CASK,
      EFCAB6, and
      PIAS2.


      See also


      Animal models of Parkinson's disease
      Mitochondria associated membranes
      Stress granule


      References




      Further reading




      External links


      Overview of all the structural information available in the PDB for UniProt: Q99497 (Protein/nucleic acid deglycase DJ-1) at the PDBe-KB.

      This article incorporates text from the United States National Library of Medicine, which is in the public domain.

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