Related Experiment Video
Updated: Jan 15, 2026

Monitoring Stub1-Mediated Pexophagy
Published on: May 12, 2023
Role of AAA-ATPase Cdc48p in peroxisomal quality control
Ismaila Francis Yusuf1, Tomasz Jeziorek1, Andrea Droste1
1Department of Systems Biochemistry, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany.
Abstract:
Most peroxisomal matrix proteins contain a type 1 peroxisomal targeting signal (PTS1), which is recognized by the cytosolic receptor Pex5p for delivery into peroxisomes. Following cargo translocation, the receptor is monoubiquitinated and recycled to the cytosol by the AAA-ATPases Pex1p and Pex6p. Defects in recycling trigger a quality control process by which the receptor is polyubiquitinated, extracted, and targeted to the proteasome for degradation by the RADAR (receptor accumulation and degradation in the absence of recycling) pathway. Although the RADAR pathway is evolutionarily conserved, it is unknown whether it is active in Saccharomyces cerevisiae. Here, we identify and characterize the RADAR pathway in S. cerevisiae and discover that the AAA-ATPases Msp1p and predominantly Cdc48p, together with its cofactors Ufd1p/Npl4p, are constituents of this pathway. We conclude that peroxisomes contain an endoplasmic reticulum-associated degradation-like protein quality control system (RADAR) in which Cdc48p and Ufd1p/Npl4p extract misfolded, polyubiquitinated receptors from the peroxisomal membrane for proteasomal degradation.
Related Concept Videos
Protein Import into the Peroxisomes
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Peroxisomes
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
DNA Damage can Stall the Cell Cycle
DNA Damage Can Stall the Cell Cycle
Export of Misfolded Proteins out of the ER

