Peroxin-7

• OMIM: 601757
• UniProt: O00628

Peroxin -7 ( Synonyms: PTS2 transporter, Pex7p ) is a transport protein that certain other proteins that are needed in peroxisomes or glyoxisomes ( in plants ), discharged into the cytoplasm in this organelle. Pex7p recognizes such to be transported proteins after they have been translated in the endoplasmic reticulum, to an amino acid sequence, the PTS2 signal. Pex7p is part of a protein complex consisting of several subcomplexes, and there are at least four transport paths in the organelles. Peroxin -7 is found in all eukaryotes and in humans in all tissue types, especially in pancreas, skeletal muscle and heart.

The transported from Peroxin -7 enzymes include Phytanoyl -CoA hydroxylase, the defect causative of Refsum syndrome, alkyl -dihydroxyacetone phosphate synthase, which catalyzes the first step in the biosynthesis of Etherphospholipiden and thus the plasmalogen synthesis, and peroxisomal thiolase 1, responsible for the final step in the β - oxidation of long chain fatty acids.

PTS2 -containing proteins are bound by Pex7p, which is present largely as a monomer in the cytoplasm, thus binds to the newly synthesized PTS2 - tagged proteins and is imported with them into the peroxisome. Pex7p then recycled into the cytoplasm.

The gene locus for the PEX7 gene is 6q21 - 22.2. Defects in this gene solved according to the residual activity of the resulting protein from either the rhizomelic chondrodysplasia punctata type 1 ( RCDP1, MIM # 215100 ) or Refsum 's syndrome.