A peroxisome (IPA:[pɛɜˈɹɒksɪˌsoʊm]) is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen peroxide (H2O2) is then formed. Peroxisomes owe their name to hydrogen peroxide generating and scavenging activities. They perform key roles in lipid metabolism and the reduction of reactive oxygen species.
Protein targeting or protein sorting is the biological mechanism by which proteins are transported to their appropriate destinations within or outside the cell. Proteins can be targeted to the inner space of an organelle, different intracellular membranes, the plasma membrane, or to the exterior of the cell via secretion. Information contained in the protein itself directs this delivery process. Correct sorting is crucial for the cell; errors or dysfunction in sorting have been linked to multiple diseases.
In biochemical protein targeting, a peroxisomal targeting signal (PTS) is a region of the peroxisomal protein that receptors recognize and bind to. It is responsible for specifying that proteins containing this motif are localised to the peroxisome.
Peroxisome biogenesis factor 1, also known as PEX1, is a protein which in humans is encoded by the PEX1 gene.
Peroxisomal biogenesis factor 19 is a protein that in humans is encoded by the PEX19 gene.
Peroxisomal membrane protein PEX14 is a protein that in humans is encoded by the PEX14 gene.
ATP-binding cassette sub-family D member 3 is a protein that in humans is encoded by the ABCD3 gene.
Peroxisomal biogenesis factor 2 is a protein that in humans is encoded by the PEX2 gene.
Peroxisome assembly protein 12 is a protein that in humans is encoded by the PEX12 gene.
Peroxisomal membrane protein PEX13 is a protein that in humans is encoded by the PEX13 gene. It located on chromosome 2 next to KIAA1841
Peroxisomal biogenesis factor 3 is a protein that in humans is encoded by the PEX3 gene.
Peroxisome assembly factor 2 is a protein that in humans is encoded by the PEX6 gene. PEX6 is an AAA ATPase that localizes to the peroxisome. PEX6 forms a hexamer with PEX1 and is recruited to the membrane by PEX26.
Peroxisome biogenesis factor 10 is a protein that in humans is encoded by the PEX10 gene. Alternative splicing results in two transcript variants encoding different isoforms.
Peroxisomal membrane protein PMP34 is a protein that in humans is encoded by the SLC25A17 gene.
Peroxisomal membrane protein PEX16 is a protein that in humans is encoded by the PEX16 gene.
Peroxisome assembly protein 26 is a protein that in humans is encoded by the PEX26 gene.
Peroxisomal membrane protein 11B is a protein that in humans is encoded by the PEX11B gene. It is involved in the regulation of peroxisome abundance.
Peroxisomal membrane protein 11A is a protein that in humans is encoded by the PEX11A gene.
Peroxisomal membrane protein 4 is a protein that in humans is encoded by the PXMP4 gene.
The tetratricopeptide repeat (TPR) is a structural motif. It consists of a degenerate 34 amino acid tandem repeat identified in a wide variety of proteins. It is found in tandem arrays of 3–16 motifs, which form scaffolds to mediate protein–protein interactions and often the assembly of multiprotein complexes. These alpha-helix pair repeats usually fold together to produce a single, linear solenoid domain called a TPR domain. Proteins with such domains include the anaphase-promoting complex (APC) subunits cdc16, cdc23 and cdc27, the NADPH oxidase subunit p67-phox, hsp90-binding immunophilins, transcription factors, the protein kinase R (PKR), the major receptor for peroxisomal matrix protein import PEX5, protein arginine methyltransferase 9 (PRMT9), and mitochondrial import proteins.
