Discovery of "scaffolds" that regulate protein degradation

Protein is one of the most important components of organism In cells, the production and folding of various proteins are mainly on endoplasmic reticulum (ER) However, in the process of protein production, there are often errors, protein may be misfolded, under environmental stress, cells may also produce and accumulate defective proteins If there are too many defective proteins accumulated in cells, it may cause diseases such as Alzheimer's disease and Parkinson's disease Therefore, defective proteins need to be identified and cleaned up in time There is a process of protein quality control in cells, in which HRD ubiquitin ligase plays a key role in the recognition of defective proteins The function of HRD ubiquitin ligase is similar to a labeling machine When it recognizes a defective protein, it will label ubiquitin on the protein, and then the protein will be degraded But so far, it is not clear how the enzyme complex can recognize and label various types of proteins In this latest study, researchers found the most important scaffold of HRD ubiquitin ligase, USA1 subunit USA1 subunit can connect all subunits of the enzyme complex to form a complete enzyme complex USA1 can connect der1 and Hrd1 subunits when recognizing and labeling some water-soluble proteins The researchers also found that HRD ubiquitin ligases can also combine with other HRD ubiquitin ligases to form a larger enzyme complex and degrade some insoluble membrane proteins This process is also completed by USA1 subunit The study was published in the journal Molecular Cell (source: Life longitude and latitude Gao Fang)