PEX2/YJL210W Summary Help

Standard Name PEX2 1
Systematic Name YJL210W
Alias CRT1 2 , 3 , PAS5 4
Feature Type ORF, Verified
Description RING-finger peroxin and E3 ubiquitin ligase; 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, 7 and see Summary Paragraph)
Name Description PEroXin 1
Chromosomal Location
ChrX:36919 to 37734 | ORF Map | GBrowse
Gbrowse
Gene Ontology 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
Regulators 12 genes
Resources
Classical genetics
null
overexpression
reduction of function
Large-scale survey
null
overexpression
Resources
63 total interaction(s) for 41 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 8
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 16
  • Co-localization: 1
  • PCA: 6

Genetic Interactions
  • Dosage Lethality: 2
  • Negative Genetic: 15
  • Positive Genetic: 5
  • Synthetic Growth Defect: 6
  • Synthetic Lethality: 1

Resources
Expression Summary
histogram
Resources
Length (a.a.) 271
Molecular Weight (Da) 30,751
Isoelectric Point (pI) 9.02
Localization
Phosphorylation PhosphoGRID | PhosphoPep Database
Structure
Homologs
sequence information
ChrX:36919 to 37734 | ORF Map | GBrowse
SGD ORF map
Last Update Coordinates: 1996-07-31 | Sequence: 1996-07-31
Subfeature details
Relative
Coordinates
Chromosomal
Coordinates
Most Recent Updates
Coordinates Sequence
CDS 1..816 36919..37734 1996-07-31 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
Resources
External Links All Associated Seq | Entrez Gene | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000003746
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) (8, 9, 10, 11 and references therein).

Pex2p is a peroxisomal membrane protein required for peroxisome biogenesis and peroxisomal matrix protein import (4, 12, 13). pex2 null mutants are viable but peroxisome deficient, and mislocalize peroxisomal matrix proteins to the cytosol (4, 14).

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 (15). 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 (15).

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 (16). 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 (16, 17).

Mutations in human PEX2 (also known as PAF-1 or PXMP3) have been associated with Zellweger Syndrome and Refsum Disease.

Last updated: 2007-06-26 Contact SGD

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) Platta HW, et al.  (2009) Pex2 and pex12 function as protein-ubiquitin ligases in peroxisomal protein import. Mol Cell Biol 29(20):5505-16
8) 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
9) Sacksteder KA and Gould SJ  (2000) The genetics of peroxisome biogenesis. Annu Rev Genet 34:623-652
10) Purdue PE and Lazarow PB  (2001) Peroxisome biogenesis. Annu Rev Cell Dev Biol 17:701-52
11) 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
12) 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
13) 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
14) Chang CC, et al.  (1999) Metabolic control of peroxisome abundance. J Cell Sci 112 ( Pt 10):1579-90
15) Agne B, et al.  (2003) Pex8p: an intraperoxisomal organizer of the peroxisomal import machinery. Mol Cell 11(3):635-46
16) 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
17) 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