Protein termini are determinants of protein stability. Proteins bearing degradation signals, or degrons, at their amino- or carboxyl-termini are eliminated by the N- or C-degron pathways, respectively. We aimed to elucidate the function of C-degron pathways and to unveil how normal proteomes are exempt from C-degron pathway-mediated destruction. Our data reveal that C-degron pathways remove mislocalized cellular proteins and cleavage products of deubiquitinating enzymes. Furthermore, the C-degron and N-degron pathways cooperate in protein removal. Proteome analysis revealed a shortfall in normal proteins targeted by C-degron pathways, but not of defective proteins, suggesting proteolysis-based immunity as a constraint for protein evolution/selection. Our work highlights the importance of protein termini for protein quality surveillance, and the relationship between the functional proteome and protein degradation pathways.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8013793 | PMC |
http://dx.doi.org/10.15252/embj.2020105846 | DOI Listing |
Sheng Li Xue Bao
December 2024
Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou 325000, China.
The N-end rule pathway is a protein degradation pathway mediated by the ubiquitin-proteasome system, which specifically targets and degrades target proteins by recognizing specific residues at the N-terminus of the proteins. The residues which play a crucial role in the N-end rule pathway are called degrons, also known as N-degrons, as they are usually unstable at the N-terminal end of the protein. Currently, several N-end rule pathways have been identified in the eukaryotes, including the Arg/N-end rule, Ac/N-end rule, and Pro/N-end rule pathways, as well as the recently discovered Gly/N-end rule pathway.
View Article and Find Full Text PDFBiochem J
December 2024
Scion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New Zealand.
Regulation of protein longevity via the ubiquitin (Ub) - proteasome pathway is fundamental to eukaryotic biology. Ubiquitin E3 ligases (E3s) interact with substrate proteins and provide specificity to the pathway. A small subset of E3s bind to specific exposed N-termini (N-degrons) and promote the ubiquitination of the bound protein.
View Article and Find Full Text PDFACS Chem Biol
December 2024
Department of Pharmacology, College of Medicine, Korea University, 73 Goryeodae-ro, Seongbuk-gu, Seoul 02841, South Korea.
Target protein degradation (TPD) is a promising strategy for catalytic downregulation of target proteins through various cellular proteolytic pathways. Despite numerous reports on novel TPD mechanisms, the discovery of target-specific ligands remains a major challenge. Unlike small-molecule ligands, aptamers offer significant advantages, owing to their SELEX-based systematic screening method.
View Article and Find Full Text PDFMol Microbiol
January 2025
Department of Biological Sciences, University of Delaware, Newark, Delaware, USA.
Drug-resistant tuberculosis infections are a major threat to global public health. The essential mycobacterial ClpC1P1P2 protease has received attention as a prospective target for novel antibacterial therapeutics. However, efforts to probe its function in cells are constrained by our limited knowledge of its physiological proteolytic repertoire.
View Article and Find Full Text PDFBiochem Pharmacol
January 2025
Amity Institute of Molecular Medicine and Stem Cell Research, Amity University Uttar Pradesh, Noida 201311, India. Electronic address:
Regulated protein degradation plays a crucial role in maintaining proteostasis along with protein refolding and compartmentalisation which collectively control biological functions. The N-end rule pathway is a major ubiquitin-dependent protein degradation system. The short-lived protein substrates containing destabilizing amino acid residues (N-degrons) are recognized by E3 ubiquitin ligases containing UBR box domains (N-recognin) for degradation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!