PEX3/YDR329C Summary Help

Standard Name PEX3 1
Systematic Name YDR329C
Alias PAS3 2
Feature Type ORF, Verified
Description Peroxisomal membrane protein (PMP); required for proper localization and stability of PMPs; anchors peroxisome retention factor Inp1p at the peroxisomal membrane; interacts with Pex19p (2, 3, 4, 5 and see Summary Paragraph)
Name Description PEroXin 1
Chromosomal Location
ChrIV:1127595 to 1126270 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All PEX3 GO evidence and references
  View Computational GO annotations for PEX3
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 2 genes
Classical genetics
reduction of function
Large-scale survey
89 total interaction(s) for 59 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 1
  • Affinity Capture-RNA: 4
  • Affinity Capture-Western: 3
  • Co-fractionation: 2
  • Co-localization: 1
  • Co-purification: 1
  • PCA: 12
  • Reconstituted Complex: 4
  • Two-hybrid: 6

Genetic Interactions
  • Dosage Growth Defect: 2
  • Dosage Lethality: 1
  • Negative Genetic: 40
  • Phenotypic Enhancement: 1
  • Positive Genetic: 4
  • Synthetic Growth Defect: 5
  • Synthetic Lethality: 1
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 441
Molecular Weight (Da) 50,675
Isoelectric Point (pI) 6.29
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIV:1127595 to 1126270 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1326 1127595..1126270 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000002737

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) (3, 6, 7, 8 and references therein).

In yeast, Pex19p and Pex3p are two proteins required for the proper localization and stability of PMPs (3). Pex3p is a peroxisomal membrane protein and is targeted to the peroxisome via the ER (2, 4). Pex3p first localizes in the ER as small dot like ER substructures before reaching the peroxisomes. Pex19p is required for the exit of Pex3p from the ER (9, 10, 11). The N-terminal region of Pex3p contains its peroxisomal targeting signal (11). pex3 null mutants completely lack detectable peroxisomal membrane structures and mislocalize the PMPs to the cytosol where they are rapidly degraded (3).

PEX3 is evolutionarily conserved,and shares sequence similarity with human PEX3. 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. Mutations in human PEX3 have been associated with Zellweger Syndrome and Refsum Disease (12).

Last updated: 2007-07-05 Contact SGD

References cited on this page View Complete Literature Guide for PEX3
1) Distel B, et al.  (1996) A unified nomenclature for peroxisome biogenesis factors. J Cell Biol 135(1):1-3
2) Hohfeld J, et al.  (1991) PAS3, a Saccharomyces cerevisiae gene encoding a peroxisomal integral membrane protein essential for peroxisome biogenesis. J Cell Biol 114(6):1167-78
3) 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
4) Gotte K, et al.  (1998) Pex19p, a farnesylated protein essential for peroxisome biogenesis. Mol Cell Biol 18(1):616-28
5) Munck JM, et al.  (2009) A dual function for Pex3p in peroxisome formation and inheritance. J Cell Biol 187(4):463-71
6) Sacksteder KA and Gould SJ  (2000) The genetics of peroxisome biogenesis. Annu Rev Genet 34:623-652
7) Purdue PE and Lazarow PB  (2001) Peroxisome biogenesis. Annu Rev Cell Dev Biol 17:701-52
8) 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
9) Kragt A, et al.  (2005) Endoplasmic reticulum-directed Pex3p routes to peroxisomes and restores peroxisome formation in a Saccharomyces cerevisiae pex3Delta strain. J Biol Chem 280(40):34350-7
10) Hoepfner D, et al.  (2005) Contribution of the endoplasmic reticulum to peroxisome formation. Cell 122(1):85-95
11) Tam YY, et al.  (2005) Pex3p initiates the formation of a preperoxisomal compartment from a subdomain of the endoplasmic reticulum in Saccharomyces cerevisiae. J Biol Chem 280(41):34933-9
12) Muntau AC, et al.  (2000) The human PEX3 gene encoding a peroxisomal assembly protein: genomic organization, positional mapping, and mutation analysis in candidate phenotypes. Biochem Biophys Res Commun 268(3):704-10