Key Points
- Researchers discovered a new quality control mechanism for peroxisomes in baker’s yeast.
- This mechanism, called the RADAR pathway, identifies and degrades faulty import receptors.
- The AAA-ATPase Cdc48p protein is central to this process, removing defective receptors for degradation.
- The RADAR pathway helps maintain peroxisome function and overall cellular health.
Scientists have uncovered a previously unknown mechanism by which cells keep their peroxisomes working properly. Peroxisomes are tiny parts inside cells that handle fat metabolism and get rid of harmful substances. To do their jobs, many enzymes need to get into these organelles correctly.
A research team at Ruhr University Bochum, Germany, led by Professor Ralf Erdmann and Dr. Ismaila Francis Yusuf, found this new quality control system in baker’s yeast, Saccharomyces cerevisiae. This mechanism is vital for maintaining peroxisome health. Their findings appeared in Cell Reports.
For the first time, the researchers identified and described the “RADAR pathway” (“Receptor Accumulation and Degradation in the Absence of Recycling”) in baker’s yeast. This pathway ensures that faulty or old import receptors are specifically identified, marked, and destroyed. Erdmann, who heads the Department of Systems Biochemistry at Ruhr University Bochum, explained, “This stops bad proteins from messing up how peroxisomes work.”
The RADAR pathway’s main player is the AAA-ATPase Cdc48p. It manages the breakdown process, along with its helpers Ufd1p and Npl4p, and another protein, the AAA-ATPase Msp1p.
The researchers showed that Cdc48p pulls defective import receptors out of the peroxisomal membrane. This allows another cellular machine, the proteasome, to break them down. In this way, the RADAR pathway is similar to the well-known ERAD system, which performs a similar quality-control function in another cellular compartment called the endoplasmic reticulum.
Erdmann emphasized, “Our results show that peroxisomes have a special quality control system that prevents problems and helps keep cells healthy. This discovery is a big step forward in understanding how peroxisomes maintain quality and how Cdc48p helps watch over proteins in cells.”
Peroxisomes are very important for human metabolism, and humans also have the RADAR pathway. This means the discovery could give us new insights into the basic ways cells maintain balance and check the quality of their proteins.
