PEX5
PEX5 (peroxisomal biogenesis factor 5, also known as PTS1R, PXR1 or peroxisome receptor 1) is the receptor that recognises the C-terminal PTS1 targeting signal on proteins destined for the peroxisome. It plays an essential role in peroxisomal protein import. Browse Assay Genie's current range of PEX5 research reagents below, or read on for the biology behind the target.
PEX5 binds the C-terminal PTS1-type tripeptide peroxisomal targeting signal, known as the SKL-type signal, and plays an essential role in peroxisomal protein import. In this way it helps deliver matrix proteins carrying that signal to the organelle. UniProt notes that it does not mediate the import of proteins carrying a C-terminal PTS2-type targeting signal, so PEX5 is specific to the PTS1 route. It is found in the cytosol and in the peroxisome matrix.
The PEX5 protein belongs to the peroxisomal targeting signal receptor family. HGNC places the PEX5 gene in two groups: tetratricopeptide repeat domain containing proteins and the peroxins. Peroxins (PEXs) are proteins that are essential for the assembly of functional peroxisomes. Alternatively spliced transcript variants encoding different isoforms have been identified. Mouse and rat each have a Pex5 ortholog.
Peroxisome biogenesis disorders (PBDs) are a genetically heterogeneous group of autosomal recessive, lethal diseases characterised by multiple defects in peroxisome function. Clinical features vary, but cells from all PBD patients show a defect in the import of one or more classes of peroxisomal matrix proteins. Defects in PEX5 are a cause of neonatal adrenoleukodystrophy (NALD) and of Zellweger syndrome (ZWS), and may be a cause of infantile Refsum disease (IRD). This makes PEX5 a central target for work on peroxisome assembly and its disorders.
PEX5 binds PTS1-type (SKL-type) signals and is essential for peroxisomal protein import, making it a core subject for studying matrix protein targeting.
As a peroxin, PEX5 is among the proteins essential for the assembly of functional peroxisomes.
Defects in PEX5 cause neonatal adrenoleukodystrophy and Zellweger syndrome, and may cause infantile Refsum disease.
PEX5 does not mediate import of PTS2-type proteins, which helps researchers separate the two peroxisomal targeting routes.
PEX5 binds the C-terminal PTS1-type tripeptide targeting signal (SKL-type) and plays an essential role in peroxisomal protein import. It is found in the cytosol and the peroxisome matrix. It does not mediate import of proteins with a C-terminal PTS2-type signal.
PEX5 stands for peroxisomal biogenesis factor 5. UniProt calls the protein peroxisomal targeting signal 1 receptor. Aliases include PTS1R and PXR1, and the previous HGNC name was peroxisome receptor 1. Alternatively spliced transcript variants encoding different isoforms have been identified.
Defects in the PEX5 gene are a cause of neonatal adrenoleukodystrophy and Zellweger syndrome, and may cause infantile Refsum disease. Mouse and rat both have a Pex5 ortholog; check the datasheet of any product for its validated reactivity.
Other peroxins involved in peroxisome assembly and protein import.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P50542; product specifications from Assay Genie datasheets.