The carboxyl terminus of the Hsc70-interacting protein (CHIP) is an Hsp70 co-chaperone as well as an E3 ubiquitin ligase that protects cells from proteotoxic stress. The abilities of CHIP to interact with Hsp70 and function as a ubiquitin ligase place CHIP at a pivotal position in the protein quality control system, where its entrance into Hsp70-substrate complexes partitions nonnative proteins toward degradation. However, the manner by which Hsp70 substrates are selected for ubiquitination by CHIP is not well understood. We discovered that CHIP possesses an intrinsic chaperone activity that enables it to selectively recognize and bind nonnative proteins. Interestingly, the chaperone function of CHIP is temperature-sensitive and is dramatically enhanced by heat stress. The ability of CHIP to recognize nonnative protein structure may aid in selection of slow folding or misfolded polypeptides for ubiquitination.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1074/jbc.M700513200 | DOI Listing |
Nat Commun
January 2025
Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
Mediator25 (MED25) has been ascribed as a signal-processing and -integrating center that controls jasmonate (JA)-induced and MYC2-dependent transcriptional output. A better understanding of the regulation of MED25 stability will undoubtedly advance our knowledge of the precise regulation of JA signaling-related transcriptional output. Here, we report that Arabidopsis MED16 activates JA-responsive gene expression by promoting MED25 stability.
View Article and Find Full Text PDFPharmacol Res
January 2025
MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou 310058, China; Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China. Electronic address:
Most of the pyroptosis inhibitors targeted Gasdermin D (GSDMD) are functioning by restraining GSDMD-N (p30) oligomerization. For the first time, this work discovered a pyroptosis inhibitor taking effect by degrading p30 and GSDMD. As the principal bioactive constituent in Erigeron breviscapus, scutellarin (SCU) assumes a pivotal role in the realm of anti-inflammatory processes.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China.
Despite substantial advances in the antitumor effects of annonaceous acetogenins (ACGs), the absence of a defined biological action mechanism remains a major barrier to their clinical application. Here, it is found that squamocin effectively depletes both EZH2 and MYC in multiple cancer cell lines, including head and neck squamous cell carcinoma, and gastric and colorectal cancer, demonstrating potent efficacy in suppressing these in vivo tumor models. Through the combination of surface plasmon resonance (SPR), differential scanning fluorimetry (DSF), and cellular thermal shift assay (CETSA), heat shock protein 90α (HSP90α) is identified as the direct binding target of squamocin.
View Article and Find Full Text PDFPLoS Pathog
January 2025
State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
Foot-and-mouth disease virus (FMDV) are small, icosahedral viruses that cause serious clinical symptoms in livestock. The FMDV VP1 protein is a key structural component, facilitating virus entry. Here, we find that the E3 ligase RNF5 interacts with VP1 and targets it for degradation through ubiquitination at the lys200 of VP1, ultimately inhibiting virus replication.
View Article and Find Full Text PDFSci Adv
January 2025
Cellular Homeostasis and Recycling, Danish Cancer Institute, DK-2100 Copenhagen, Denmark.
Nutrient deprivation is a major trigger of autophagy, a conserved quality control and recycling process essential for cellular and tissue homeostasis. In a high-content image-based screen of the human ubiquitome, we here identify the E3 ligase Pellino 3 (PELI3) as a crucial regulator of starvation-induced autophagy. Mechanistically, PELI3 localizes to autophagic membranes, where it interacts with the ATG8 proteins through an LC3-interacting region (LIR).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!