26S proteasome is a large multi-subunit protein complex involved in proteolytic degradation of proteins. In addition to its canonical proteolytic activity, the proteasome is also associated with recently characterized endoribonuclease (endo- RNAse) activity. However, neither functional significance, nor the mechanisms of its regulation are currently known. In this report, we show that 26S proteasome is able to hydrolyze various cellular RNAs, including AU-rich mRNA of c-myc and c-fos. The endonucleolytic degradation of these mRNAs is exerted by one of the 26S proteasome subunits, PSMA5 (alpha5). The RNAse activity of 26S proteasome is differentially affected by various extra-cellular signals. Moreover, this activity contributes to the process of degradation of c-myc mRNA during induced differentiation of K562 cells, and may be controlled by phosphorylation of the adjacent subunits, PSMA1 (alpha6) and PSMA3 (alpha7). Collectively, the data presented in this report suggest a causal link between cell signalling pathways, endo-RNAse activity of the 26S proteasome complex and metabolism of cellular RNAs.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.4161/cc.9.4.10829 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The Role of E3 Ubiquitin Ligase Gene in Ubiquitination Modification of Protein and Its Potential Function in Plant Growth, Development, Secondary Metabolism, and Stress Response.
Int J Mol Sci
January 2025
College of Grassland Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
As a crucial post-translational modification (PTM), protein ubiquitination mediates the breakdown of particular proteins, which plays a pivotal role in a large number of biological processes including plant growth, development, and stress response. The ubiquitin-proteasome system (UPS) consists of ubiquitin (Ub), ubiquitinase, deubiquitinating enzyme (DUB), and 26S proteasome mediates more than 80% of protein degradation for protein turnover in plants. For the ubiquitinases, including ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2), and ubiquitin ligase (E3), the FBK (F-box Kelch repeat protein) is an essential component of multi-subunit E3 ligase SCF (Skp1-Cullin 1-F-box) involved in the specific recognition of target proteins in the UPS.
View Article and Find Full Text PDFTetrandrine targeting SIRT5 exerts anti-melanoma properties via inducing ROS, ER stress, and blocked autophagy.
J Pharm Anal
October 2024
Department of Dermatology, The Third Hospital of Hebei Medical University, Shijiazhuang, 050051, China.
Tetrandrine (TET), a natural bisbenzyl isoquinoline alkaloid extracted from S. Moore, has diverse pharmacological effects. However, its effects on melanoma remain unclear.
View Article and Find Full Text PDF26S Proteasome Subunit SlPBB2 Regulates Fruit Development and Ripening in Tomato.
J Agric Food Chem
January 2025
Fruit Biology Laboratory, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Proteasomes are protein complexes responsible for degrading unneeded or damaged proteins through proteolysis and play critical roles in regulating plant development and response to environmental stresses. However, it is still unclear whether proteasomes regulate fruit development and ripening. In this study, we investigated the function of a core proteasome subunit, SlPBB2, in tomato fruit.
View Article and Find Full Text PDFHarnessing the ubiquitin proteasome system as a key player in stem cell biology.
Biofactors
January 2025
Biochemistry Department, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt.
Intracellular proteins take part in almost every body function; thus, protein homeostasis is of utmost importance. The ubiquitin proteasome system (UPS) has a fundamental role in protein homeostasis. Its main role is to selectively eradicate impaired or misfolded proteins, thus halting any damage that could arise from the accumulation of these malfunctioning proteins.
View Article and Find Full Text PDF19S proteasome loss causes monopolar spindles through ubiquitin-independent KIF11 degradation.
bioRxiv
January 2025
Whitehead Institute for Biomedical Research, Cambridge, MA 02142.
To direct regulated protein degradation, the 26S proteasome recognizes ubiquitinated substrates through its 19S particle and then degrades them in the 20S enzymatic core. Despite this close interdependency between proteasome subunits, we demonstrate that knockouts from different proteasome subcomplexes result in distinct highly cellular phenotypes. In particular, depletion of 19S PSMD lid proteins, but not that of other proteasome subunits, prevents bipolar spindle assembly during mitosis, resulting in a mitotic arrest.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!