PEX2 BASIC INFORMATION
| Standard Name | PEX2 1 |
|---|---|
| Systematic Name | YJL210W |
| Alias | CRT1 2 , 3 , PAS5 4 |
| Feature Type | ORF, Verified |
| Description | RING-finger peroxin, peroxisomal membrane protein with a C-terminal zinc-binding RING domain, forms translocation subcomplex with Pex10p and Pex12p which functions in peroxisomal matrix protein import (5, 6 and see Summary Paragraph)
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| Name Description | PEroXin 1 |
| GO Annotations | All PEX2 GO evidence and references |
|---|---|
| View Computational GO annotations for PEX2 | |
| Molecular Function | |
| Manually curated | |
| Biological Process | |
| Manually curated | |
| Cellular Component | |
| Manually curated |
| Mutant Phenotype | All PEX2 Phenotype details and references |
|---|---|
| Classical genetics | |
| null | |
| overexpression | |
| Large-scale survey | |
| null | |
| overexpression |
| Interactions | PEX2 All interactions details and references |
|---|---|
| 21 total interaction(s) for 15 unique genes/features. | |
| Physical Interactions |
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| Genetic Interactions |
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| External Links | All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | UniProtKB |
|---|
| Primary SGDID | S000003746 |
|---|
ADDITIONAL INFORMATION for PEX2
NOMENCLATURE CONFLICT NOTE
| Name | Relevance | Description |
|---|---|---|
| RFX1 | Nomenclature conflict | CRT1 has been used in the literature to refer to both RFX1/YLR176C, which encodes a DNA binding protein, and PEX2/YJL210W which encodes a peroxisomal protein. |
SUMMARY PARAGRAPH for PEX2
The biogenesis of peroxisomes requires a group of protein factors referred to as peroxins which are encoded by the PEX genes. Peroxisomal proteins are synthesized on free polyribosomes and imported posttranslationally. The transport of peroxisomal matrix proteins from the cytoplasm to the peroxisome is mediated by two peroxisome-targeting signal sequences (PTS1 and PTS2). Peroxisomal membrane proteins (PMPs) are imported independently of the matrix proteins by a distinct mechanism mediated by the membrane PTS signal (mPTS) (7, 8, 9, 10 and references therein).
Pex2p is a peroxisomal membrane protein required for peroxisome biogenesis and peroxisomal matrix protein import (4, 11, 12). pex2 null mutants are viable but peroxisome deficient, and mislocalize peroxisomal matrix proteins to the cytosol (4, 13).
Two subcomplexes of the peroxisomal import machinery have been defined: the docking subcomplex comprises Pex14p, Pex17p, and Pex13p, while the translocation subcomplex contains Pex2p, Pex10p, and Pex12p. The proteins of the translocation complex expose their RING finger domains to the outer face of the peroxisomal membrane, and act downstream of Pex14p, Pex17p, and Pex13p during the peroxisomal protein import process (14). Association of both subcomplexes into a larger import complex requires Pex8p, an intraperoxisomal protein. Pex8p organizes the formation of the larger import complex from the trans side of the peroxisomal membrane and thus might enable functional communication between both sides of the membrane (14).
PEX2 is transcribed from two different promoters, one induced during peroxisome proliferation and the other during the induction of mitochondrial function. The shorter transcripts initiate downstream of the first in-frame ATG, and, consistent with the different conditions of induction, the N-terminus of the shorter protein not only lacks the longer protein's acidic amino-terminal domain, but rather contains basic and hydroxylated amino acids, a signature of mitochondrial targeting sequences (3). However, it is unknown whether the shorter transcript actually gives rise to a mitochondrially targeted form of Pex2p, or what the role of such a protein in mitochondrial function might be.
The human peroxisome biogenesis disorders (PBDs) are a group of genetically heterogeneous diseases characterized by severe mental retardation, neuronal, hepatic and renal abnormalities, and death in early infancy (15). Clinical features of PBD patients vary, but all exhibit a defect in the import of one or more classes of peroxisomal matrix proteins. This cellular phenotype is shared by yeast pex mutants, and human orthologs of yeast PEX genes are defective in some groups of PBD patients (15, 16).
Mutations in human PEX2 (also known as PAF-1 or PXMP3) have been associated with Zellweger Syndrome and Refsum Disease.
REFERENCES CITED ON THIS PAGE [View Complete Literature Guide for PEX2]
| 1) | Distel B, et al. (1996) A unified nomenclature for peroxisome biogenesis factors. J Cell Biol 135(1):1-3 |
| 2) | Vandenbol M, et al. (1994) Sequence analysis of a 40.2 kb DNA fragment located near the left telomere of yeast chromosome X. Yeast 10(12):1657-62 |
| 3) | Liu Y, et al. (1996) Independent regulation of full-length and 5'-truncated PAS5 mRNAs in Saccharomyces cerevisiae. Yeast 12(2):135-43 |
| 4) | Van der Leij I, et al. (1992) Isolation of peroxisome assembly mutants from Saccharomyces cerevisiae with different morphologies using a novel positive selection procedure. J Cell Biol 119(1):153-62 |
| 5) | Gould SJ and Valle D (2000) Peroxisome biogenesis disorders: genetics and cell biology. Trends Genet 16(8):340-5 |
| 6) | Hazra PP, et al. (2002) Peroxisome remnants in pex3delta cells and the requirement of Pex3p for interactions between the peroxisomal docking and translocation subcomplexes. Traffic 3(8):560-74 |
| 7) | Hettema EH, et al. (2000) Saccharomyces cerevisiae pex3p and pex19p are required for proper localization and stability of peroxisomal membrane proteins. EMBO J 19(2):223-33 |
| 8) | Sacksteder KA and Gould SJ (2000) The genetics of peroxisome biogenesis. Annu Rev Genet 34:623-652 |
| 9) | Purdue PE and Lazarow PB (2001) Peroxisome biogenesis. Annu Rev Cell Dev Biol 17:701-52 |
| 10) | Fujiki Y, et al. (2006) Import of peroxisomal membrane proteins: The interplay of Pex3p- and Pex19p-mediated interactions. Biochim Biophys Acta 1763(12):1639-46 |
| 11) | Kiel JA, et al. (2005) Ubiquitination of the peroxisomal targeting signal type 1 receptor, Pex5p, suggests the presence of a quality control mechanism during peroxisomal matrix protein import. J Biol Chem 280(3):1921-30 |
| 12) | Eckert JH and Johnsson N (2003) Pex10p links the ubiquitin conjugating enzyme Pex4p to the protein import machinery of the peroxisome. J Cell Sci 116(Pt 17):3623-34 |
| 13) | Chang CC, et al. (1999) Metabolic control of peroxisome abundance. J Cell Sci 112 ( Pt 10):1579-90 |
| 14) | Agne B, et al. (2003) Pex8p: an intraperoxisomal organizer of the peroxisomal import machinery. Mol Cell 11(3):635-46 |
| 15) | Warren DS, et al. (1998) Identification of PEX10, the gene defective in complementation group 7 of the peroxisome-biogenesis disorders. Am J Hum Genet 63(2):347-59 |
| 16) | Chang CC, et al. (1997) Isolation of the human PEX12 gene, mutated in group 3 of the peroxisome biogenesis disorders. Nat Genet 15(4):385-8 |




